Then Jacob made a vow, saying, “If God will be with me and watch over me on this journey, and if He will provide me with food to eat and clothes to wear,
20. And Jacob vowed a vow. The design of this vow was, that Jacob would manifest his gratitude, if God should prove favorable unto him. Thus they offered peace-offerings under the law, to testify their gratitude; and since thanksgiving is a sacrifice of a sweet odour, the Lord declares vows of this nature to be acceptable to him; and therefore we must also have respect...
God manifested himself and his favour to Jacob when he was asleep and purely passive; for the spirit, like the wind, blows when and where he listeth, and God's grace, like the dew, tarrieth not for the sons of men, Mic 5:7.
Commenting on Genesis 28:16-22
And Jacob vowed a vow,.... Which is the first vow we read of in Scripture: saying, if God will be with me; the word if is not a sign of doubting, but is either an adverb of time, and may be rendered, "when God shall be with me" (t); or as a supposition, expressive of an inference or conclusion drawn, "seeing God will be with...