Jacob cast himself down before the Eben Shetiyah, and entreated God to fulfil the promise He had given him, and also he prayed that God grant him honorable sustenance. For God had not mentioned bread to eat and raiment to put on, that Jacob might learn to have faith in the Lord. Then he vowed to give the tenth of all he owned unto God, if He would but grant his petition. Thus Jacob was the first to take a vow upon himself, and the first, too, to separate the tithe from his income.
God had promised him almost all that is desirable, but he feared he might forfeit the pledged blessings through his sinfulness, and again he prayed earnestly that God bring him back to his father's house unimpaired in body, possessions, and knowledge, and guard him, in the strange land whither he was going, against idolatry, an immoral life, and bloodshed.