According to Midrash “Yalkut Shimoni,” on Shemot, Yissachar was born on the tenth of Av, and lived 122 years. Yissachar is the fifth son that Leah bears for Yaakov, and his ninth son overall.
Among the Blessings and Prophecies of Yaakov to his sons, we find, “Yissachar is a strong-boned donkey… He saw tranquility that it was good, and the land that it was pleasant, yet he bent his shoulder to bear…’ (Bereshit 49:14-15) This is a rather enigmatic blessing; hence there are a number of interpretations:
One takes the verses literally, interpreting them in an agricultural context, picturing Yissachar as a hard-working laborer on his inheritance in the Land of Israel.
Rashi interprets the Blessing in the context of Yissachar being a hard laborer in the field of Torah. He will “bend his shoulder” to bear the yoke of Torah, and will have great success in that field. He will become a source of knowledge for the Jewish People, and will produce from his ranks two hundred Heads of the “Sanhedrin” (Jewish Supreme Court), as we find in “Divrei HaYamim ‘Aleph’ 12:33, “And from the descendants of Yissachar there were those who had great insight into the calculation of times, who were able to say what the People of Israel should do – two hundred Heads…” While they had tremendous general knowledge of Torah and were able to resolve difficult problems, their specialty was the Laws of Leap Year (by addition of a second Month of Adar), and the determination of when the beginning of a Month (Rosh Chodesh) occurs. Both those types of information are crucial for the determination of the Hebrew Calendar; specifically regarding when the Festivals Pesach, Shavuot and Sukkot occur.
Onkelos understands these Blessings of Yaakov as referring to the fact that part of the boundary of the inheritance of the Tribe of Yissachar in “Eretz Yisrael” would be on the border, and they were frequently involved in wars with the enemies of Israel, of which the outcome would generally be that the enemy would be defeated.
In his blessing to the Tribe of Yissachar, Moshe Rabbeinu joins Yissachar with his brother Zevulun in his final words to the Tribes, foreseeing a partnership relationship where Zevulun devotes itself mainly to traveling the seas in pursuit of commerce, while supporting the Tribe of his brother, Yissachar, which devotes itself to the study of Torah; and the heavenly reward for the study of Torah is split between them. Moshe says, “…Rejoice, O Zevulun in your seafaring excursions, and Yissachar in your tents.” (Devarim 33:18)
Rashi cites another Midrash “Sifri” that explains how the Yissachar-Zevulun partnership operated as a “spiritual magnet.” “The great merchandising ability of the Tribe of Zevulun will draw traders from many nations to do business with its members. Once they got to the territory of Zevulun, they would say to each other, ‘Let us go and observe how this nation worships its G-d.’ They would proceed to Yerushalayim to observe the practices of the Jewish People (as taught by the great Torah scholars of the Tribe of Yissachar), and contrast the worship of one G-d and the unified social structure of the Jewish People with their own polytheistic religions and debased national cultures. And they would convert to Judaism.”
The Torah scholarship of the Tribe of Yissachar was so great that the Sages said, “No scholar could be found who would provide guidance in Torah Law besides a descendant of the Tribe of Levi or the Tribe of Yissachar.”
In the Period of the “Shophtim” (Judges), the Prophetess Devorah composed a song following the defeat of Yavin, King of Canaan, and his general, Sisera, with his nine-hundred chariots. In that song, she praised the Tribe of Yissachar for their bravery.
“…And the princes of Yissachar were with Devorah;
As was Yissachar, so was Barak;
Into the valley they rushed forth, at his feet…”
The inheritance of the Tribe of Yissachar in the Land of Israel was adjacent to and just south of the land of the Tribe of Zevulun, extending from the Yarden (Jordan) River westward to the Mediterranean. Yissachar, the great son of Yaakov, who was the founder of the Tribe that bore his name and who provided the inspiration for its future development, was buried near his beloved brother, Zevulun, in Zidon.