The Prophet’s -upon him blessings and peace- custodianship of Ali –Allah be well-pleased with him-.
Abu Talib was in financial duress, being the head of a large household. It was owing to this that the Blessed Prophet -upon him blessings and peace- went to his other uncle Abbas –Allah is well-pleased with him- and suggested:
“As you know uncle, your brother Abu Talib manages a large family and the drought and famine have left him in need like most. Why don’t we go to him and talk him into giving two of his little ones over to our custody, to relieve him of some of his responsibility?”
Abbas –Allah be well-pleased with him- accepted the benevolent suggestion, and together they went to Abu Talib, who after hearing the offer, said:
“Apart from Aqil, you can take any of the children you like”, he said.
Muhammad -upon him blessings and peace- eventually took Ali, while Abbas took his brother Jafar Allah to be well-pleased with them-. Ali –Allah be well-pleased with him- was raised by his generous caretaker until the beginning of prophethood. (Ibn Hisham, I, 264)