Moses
Genesis 21:17ESV·traditional attribution

And God heard the voice of the boy, and the angel of God called to Hagar from heaven and said to her, “What troubles you, Hagar? Fear not, for God has heard the voice of the boy where he is.

John Calvin Reformed @genevareformer

17. God heard the voice of the lad . Moses had said before that Hagar wept: how is it then, that, disregarding her tears, God only hears the voice of the lad ? If we should say, that the mother did not deserve to receive a favorable answer to her prayers; her son, certainly, was in no degree more worthy.

Matthew Henry Presbyterian @wholebiblehenry

Here is, I. The casting out of the bond-woman, and her son from the family of Abraham, Gen 21:14. Abraham's obedience to the divine command in this matter was speedy - early in the morning, we may suppose immediately after he had, in the night's visions, received orders to do this.

Commenting on Genesis 21:14-21

John Gill Reformed Baptist @doctorgill

Arise, lift up the lad,.... She had set herself down at some distance, and now she is bid to rise up and go to the place where she had left her son, and raise aim up from the ground, on which he lay along: and hold him in thine hand: or take hold on him with thine hand, and hold him up with it, he...