"The elders of Moab and Midian, versed in occult arts, went to Bilaam, conveying to him Balak's message. `Spend the night,' he replied to them, `and when G-d speaks to me, I will be able to give you an answer.' ... G-d said to Bilaam, `Do not go with them. Do not curse them, because it is a blessed nation'. When Bilaam got up in the morning, he said to Balak's dignitaries, `Go home! G-d refuses to let me go with you.' " (Num. 22:7-8,12-13)
Interestingly, Bilaam was approached by "the elders of Moab and Midian", but in the morning he spoke to Balak's dignitaries! What happened to the elders of Midian?
The Talmud (Sanhedrin 105a) tells us that as soon as the elders of Midian heard that Bilaam was going to ask G-d first, they immediately left. They said: "There is no father that hates his son!" They were already aware of the relationship G-d had with the Children of Israel, and realized that Balak's cause was lost.
The question we must ask is, if the elders of Midian were somehow aware of the love G-d has for the Jews, why then was Bilaam, a prophet, not aware?
The answer is that Bilaam, and the rest of us for that matter, are only aware of what we want to be aware of! Bilaam, in addition to being a sorcerer, was a prophet, and in fact clearly communicated with G-d, yet he was blind to the facts because he had no desire to know them. Even after G-d replied to him and told him that he could not curse the people, he returned to ask Him again, and even after his ass had spoken to him, and after his own mouth had, in spite of himself, uttered a blessing instead of a curse (twice!), he still did not seem to grasp that it was not G-d's will for him to curse the people of Israel.
In our prayers we ask G-d to give us a "heart of understanding".Although the heart is the source of emotion and desire, and the mind is the seat of intellect and understanding, we nevertheless pray for a heart of understanding, for otherwise we will only believe what we want to believe.