John Calvin Commentary Genesis 32:11

"Deliver me, I pray thee, from the hand of my brother, from the hand of Esau: for I fear him, lest he come and smite me, the mother with the children." — Genesis 32:11 (ASV)

Deliver me. After he has declared himself to be bound by so many of God’s benefits that he cannot boast of his own merits, and so raised his mind to higher expectation, he now mentions his own necessity. It is as if he would say, “O Lord, unless you choose to reduce so many excellent gifts to nothing, now is the time for you to help me, and to avert the destruction which, through my brother, is suspended over me.” But having so expressed his fear, he adds a clause concerning the blessing promised him, so that he may confirm himself in the promises made to him.

To slay the mother with the children, I suppose was a proverbial saying among the Jews, which means to leave nothing remaining. It is a metaphor taken from birds, when hawks seize the young with their mothers, and empty the whole nest.