Jacob took twelve stones from the altar on which his father Isaac had lain bound as a sacrifice, and he said: "It was the purpose of God to let twelve tribes arise, but they have not been begotten by Abraham or Isaac. If, now, these twelve stones will unite into a single one, then shall I know for a certainty that I am destined to become the father of the twelve tribes." At this time the second miracle came to pass, the twelve stones joined themselves together and made one, which he put under his head, and at once it became soft and downy like a pillow.
It was well that he had a comfortable couch. He was in great need of rest, for it was the first night in fourteen years that he did not keep vigils. During all those years, passed in Eber's house of learning, he had devoted the nights to study. And for twenty years to come he was not to sleep, for while he was with his uncle Laban, he spent all the night and every night reciting the Psalms.