John Calvin Commentary Genesis 32:7

"Then Jacob was greatly afraid and was distressed: and he divided the people that were with him, and the flocks, and the herds, and the camels, into two companies;" — Genesis 32:7 (ASV)

And he divided the people. Moses relates that Jacob formed his plans according to the existing circumstances. He divided his family into two parts and put his female servants in the foremost place, so that they might bear the first assault, if necessary; but he placed his free wives further from the danger. From this, indeed, we gather that Jacob was not so overcome with fear as to be unable to arrange his plans.

We know that when panic seizes the mind, it is deprived of discretion, and those who ought to look after their own concerns become dazed and unresponsive. Therefore, it proceeded from the spirit of faith that Jacob placed a certain distance between the two parts of his family, so that if any destruction approached, the entire seed of the Church might not perish. For by this plan, he offered half of his family to the slaughter, so that, eventually, the promised inheritance might come to the remainder who survived.