Genesis 25:21

And Isaac intreated the Lord for his wife because she was barren; and the Lord was intreated of him, and Rebekah, his wife, conceived. It is the Lord who grants issue to married people, but the blessing of children, like all other blessings, must be prayed for. Just as Isaac had prayed for a pious wife, so he also prayed for children, and undoubtedly for pious children, just as Luther teaches in his explanation of the Fourth Petition.

And Israel journeyed, and spread his tent beyond the tower of Edar. He struck his tent, and he pitched his tent: the usual way of describing a nomadic form of life. This was south of Bethlehem, and the tower of the flocks was built for their protection, in a region eminently suited for pasturage.