“Yosef could hold in his emotions. Since all his attendants were present, he cried out, “Have everyone leave my presence!” Thus no one else was with him when Yosef revealed himself to his brothers.” (Bersheit 45:1)
He commands his servants and ministers to leave him. He is prepared to reveal himself to his brothers.
Why did Yosef command his servants to leave? The Torah provides an ambiguous response. The pasuk seem to indicate two reasons. First, Yosef could no longer restrain his feeling. Second, he planned to reveal himself to his brothers. What is the connection between these two factors?
Our Sages offer different explanations. Rashi reinterprets the passage. He explains that Yosef was not overcome with emotion. He offers an alternative translation of the opening phrase of the passage. “Yosef could not endure.” The Torah is telling us that he could not endure displaying his brothers’ shame. He was prepared to reveal himself. He would tell his brothers that he was Yosef. He was the brother they had plotted against and sold into slavery. The brothers would be confronted with the injustice of their behavior. Yosef did not want the Egyptians to learn of his brothers’ intrigues. He did not want to disgrace his brothers in the presence of the Egyptians. 
Rabbaynu Avraham ibn Ezra offers another explanation. He accepts Rashi’s assertion that Yosef did not want the Egyptians present when he confronted his brothers. However, Ibn Ezra explains that Yosef was overcome. Yosef was prepared to reveal himself. Ideally, he would have waited until he was alone with his brothers. However, he could not wait for this opportunity. Why could he not delay the revelation? He was overcome. He could no longer maintain his disguise. Therefore, he was anxious to remove his servants.
Nachmanides offers a very interested variation on these explanations. He also agrees that Yosef did not want the Egyptians present at the moment of his revelation. However, he offers an alternative explanation for this concern. Yosef planned to bring his father and brothers down to Egypt. His plan would require the acquiescence of Paroh and the Egyptian people. He expected Egypt to open its borders to foreigners. This new group must be positively represented. Yosef needed to convince the Egyptians that they should not fear these foreigners. The Egyptians could not discover that Yosef’s family had intrigued against him and showed disregard for their father’s feelings. This knowledge would evoke suspicions. How could the Egyptians trust the loyalty of a family that sold a member into slavery? Would the brothers be faithful to Paroh? They had not been faithful to their own father! In order to avoid creating these suspicions, Yosef hid from the Egyptians the events leading to his bondage.
“And Yosef said to his brothers, “I am Yosef. Is my father still alive?” And his brothers were not able to respond to him because they were startled.” (Beresheit 45:3)
Binyamin has been accused of stealing Yosef’s goblet. Yosef has pronounced Binyamin’s punishment. Binyamin will not be permitted to return to Canaan. He will remain in Egypt in servitude. Yehudah appeals to Yosef to spare Binyamin. He asks Yosef to allow Binyamin to return to Canaan with the brothers. Yehudah will remain in Egypt and serve as Yosef’s servant. He will accept upon himself the punishment due Binyamin.
Yosef reveals himself to his brothers. He tells them that he is their brother, Yosef. He asks if his father Yaakov is still alive.
Yosef’s question is odd. Yehudah has argued that Yosef should spare Binyamin. He argued that the loss of Binyamin would destroy Yaakov. Obviously, Yaakov is still alive. Why does Yosef ask Yehudah for a further confirmation of this fact?
There are various answers to this question. The most obvious is that Yosef suspected that Yehudah might have been dishonest. Yehudah was begging Yosef to spare Binyamin. Perhaps, Yehudah had claimed that Yaakov was alive in order to support his plea for Binyamin’s freedom. He asserted that Binyamin should be freed in order to spare Yaakov. This suggested the possibility that Yaakov had really died. However, Yehudah was asserting he was still alive in an attempt to save Binyamin.
There is another possible explanation of Yosef’s suspicion. In order to understand this possibility, we must explain a previous incident.
Yosef’s brothers originally entered Egypt in order to purchase provisions. Yosef accused them of spying. The brothers responded by describing their family structure. They told Yosef that they were all sons of a single father. They told Yosef they had a younger brother who had not accompanied them. This brother was in Canaan with their father.
Yosef asserted that their narrative supported his accusation. They could only clear themselves by bringing their youngest brother to Egypt.
This entire exchange seems bizarre! First, why did the brothers respond to Yosef’s accusations with an account of their family structure? What relevance does this response have to the accusation? Second, Yosef rejected their response. He claimed that their reply supported his accusation. How did the brother’s description of their family support Yosef’s charge? Third, Yosef demanded that the brothers clear themselves of suspicion by bringing their youngest brother to Egypt. How would bringing Binyamin to Egypt prove the brothers’ innocence?
Gershonides offers a comprehensive response to these questions. Yosef accused the brothers of spying. The brothers responded that they shared a single father. Gershonides explains this response. Their account of their family was an attempt to persuade Yosef that they were not really spies. Spying is dangerous. A father might allow one of his children to engage in such an endeavor. Perhaps, in a desperate situation, he would allow a few of his children to engage in such a perilous mission. However, a father would not risk the lives of all of his children. The brothers argued on this basis that they could not be spies. They are the sons of a single father. He would not allow ten of his eleven sons to risk their lives as spies.
Yosef responded that their account of their family actually undermined their claim of innocence. Their father had not allowed all of his sons to travel to Egypt. He had insisted that one son remain home with him. If they had come to purchase provisions, eleven sons could accomplish this more than ten. Keeping one son at home indicated that their father perceived their mission to Egypt as dangerous. Therefore, he had insisted that one son be spared this peril. Why was their mission dangerous? They were spies! One son had been held back. If misfortune befell the brothers, one son would be spared.
Yosef demanded that the brothers demonstrate their innocence. This could be accomplished by returning with their remaining brother. This would prove that they had not come to Egypt on a dangerous spying mission. Their father would only allow all of his sons to travel to Egypt if their mission was truly innocent and harmless.
Based on Gershonides’ explanation of the dialogue between Yosef and his brothers, we can understand Yosef’s question in our pasuk. Yehudah told Yosef that their father was alive. Yosef recognized that this assertion could be a response to the test he had formulated. Bringing Binyamin to Egypt was designed to prove that the brothers were not spies. Their father, allowing all of his sons to travel to Egypt, would prove this. In other words, Binyamin’s presence could only establish their innocence if Yaakov was alive. Yosef feared that Yehudah had reported that Yaakov was alive in order to avoid undermining their defense.
Now, Yosef has revealed himself to the brothers. They no longer need to fear the accusation of spying. They can be honest with Yosef. Therefore, Yosef again asks if his father is alive.
“And Yosef harnessed his chariot and he went up to greet his father Yisrael at Goshen. And he appeared to him and he fell upon his shoulders and he wept upon his shoulders for a long time.” (Beresheit 46:29)
Yosef is finally to be reunited with his father Yaakov. The pasuk tells us that he harnessed his chariot. Our Sages comment that although Yosef was a ruler in Egypt, he personally prepared his chariot. This was an indication of his deep respect for his father. He greets his father and is overcome by emotion. He falls upon Yaakov’s shoulders and weeps.
This reunion is not the first indication of Yosef’s deep concern and love for Yaakov. He had repeatedly asked the brothers to report upon Yaakov’s well-being.
Yosef was a person of great authority in Egypt. He was second only to Paroh. It is clear that he had complete freedom of action. He loved his father. He certainly knew of the sorrow his father must have experienced in believing that his son was dead. It would seem Yosef could have easily contacted Yaakov earlier. Why did Yosef not communicate with Yaakov before this point?
Rabbaynu Avraham ben HaRambam makes an enigmatic comment about this issue. He explains that Yosef recognized that Divine Providence was at work. He felt that revealing himself to his father would interfere with Hashem’s plan.
The difficulty in Rabbaynu Avraham ben HaRambam’s explanation is that it is based upon a number of unstated premises. The explanation assumes that Yosef had some understanding of the nature of Hashem’s plan. Based upon this understanding, Yosef concluded that he could not communicate to Yaakov. Any communication would undermine the ultimate objective. Rabbaynu Avraham ben HaRambam leaves it to us to deduce Yosef’s theory regarding Hashem’s plan.
Perhaps we can understand Yosef’s theory if we return to his dreams as a youth. In these dreams Yosef discovered that some day he would become the leader of the brothers. Even his father would be under his authority. The brothers regarded these dreams as youthful fantasies. But Yosef never doubted the authenticity of his visions.
Yosef realized that there were two possible paths to the fulfillment of his dreams. He could ascent to a position of authority over the brothers through their recognition of his leadership. This path was closed by the enmity that developed between Yosef and the brothers.
The other path was far more radical. It required that Yosef achieve power and authority independently. Once this position was achieved events would cause the brothers to submit to Yosef’s leadership. This second path would require Yosef’s separation from his family until the proper moment. Then, Yosef must wait for the moment at which his brothers would be forced to submit themselves to his leadership.
Yosef understood that the decision of his brothers to sell him blocked the first path. He would not achieve his proper role through the willing recognition of the brothers. He concluded that his experiences in Egypt, in some way, were a journey along the second path. These experiences would ultimately end with a reunification with the brothers. However, for this reunification to result in his ascension to a position of power among the brother, he must patiently await the proper moment.
Yosef could not contact his family before this proper moment. Any reunification, before the intended time would undermine the plan of Hashem.
 Rabbaynu Shlomo ben Yitzchak (Rashi), Commentary on Sefer Beresheit 45:1.  Rabbaynu Avraham ibn Ezra, Commentary on Sefer Beresheit, 45:1.  Rabbaynu Moshe ben Nachman (Ramban / Nachmanides), Commentary on Sefer Beresheit 45:1.  Rabbaynu Levi ben Gershon (Ralbag / Gershonides), Commentary on Sefer Beresheit, (Mosad HaRav Kook, 1994), pp. 235-236.  Midrash Rabba, Sefer Beresheit 55:8.