Genesis 21:14

But was the just Abraham inhumane in that he did not even supply Hagar and the boy with a donkey, with all the cattle he possessed? Some say it was a gesture of kindness, so that she would not have to look after the donkey; others say that he did this believing that God would protect the boy. But why does he throw her out in the first place? Was it not that he wished to have peace with his wife? And indeed he really did not want to send her away at all, for it is written that the thing appeared extremely harsh to Abraham. So he would not have done what he did except for the fact that God said to him, let not this matter trouble you, etc.

(Verse 14) And he took bread and a skin of water, and gave it to Hagar, putting it on her shoulder, along with the child, and sent her away. When Isaac was born, Ishmael was thirteen years old. And after he was weaned, he was expelled from the house with his mother. However, among the Hebrews, there are different opinions, with some claiming that the time for weaning is set at the fifth year, and others claiming the twelfth year. Therefore, to choose a shorter age, we have calculated that Ishmael was expelled with his mother after eighteen years, and it is no longer possible for him to have sat on his mother's lap as a young man. So it is true that the Hebrew language has the word 'infant' to refer to every child in relation to their parents. It is not surprising that a foreign language has its own peculiarities, since even today in Rome all children are called 'infants'. Therefore, Abraham placed bread and a skin of water on Hagar's shoulder and, having done this, he gave the child to his mother, that is, he handed him over to her, entrusted him to her care, and thus sent him out of the house. As for what follows:

RETURN OF HAGAR AND ISHMAEL. — And Abraham rose up in the morning and took loaves and a skin of water, and gave them to Hagar, and he put the child on her shoulder, and sent her away . It’s often asked how he put such a big boy on her shoulder. For Ishmael had been circumcised at the age of thirteen, before Isaac was born, when Abraham was ninety-nine years old (Cf. Gen. 17:17-24). Isaac was born when his father was one hundred years old. Ishmael was playing with Isaac when Sarah saw him with concern (Cf. Gen. 21:9), Isaac was already a big boy, since he had already been weaned. For all this, it is evident that Ishmael was more than sixteen years old when he was expelled with his mother from his father's house. Now, even if we consider that it was said in recapitulation that he played with Isaac when he was still very young, before being weaned, nevertheless, it is too absurd to believe that a child, even in this case of more than thirteen years, had been placed on the shoulder of his mother, with a wineskin and some loaves. The question is solved very easily if we do not understand "put", but "gave". For Abraham, as it is written, gave to his mother loaves and a wineskin, which she put on her shoulder. When it was added and said: also the child, we must understand was "gave" the same that gave her the loaves and the wineskin, and he did not "put the child on her shoulder." [