John Gill Commentary Genesis 28:15

"And, behold, I am with thee, and will keep thee, whithersoever thou goest, and will bring thee again into this land. For I will not leave thee, until I have done that which I have spoken to thee of." — Genesis 28:15 (ASV)

And, behold, I [am] with you. Though alone, at a distance from his father's house, no friend to keep him company, or servant to attend him; but the presence of God here promised is abundantly more than an equivalent for all this.

and will keep you in all [places], where you go; from beasts of prey, in lonesome places through which he might travel; from thieves and robbers, to whom he might be exposed; from his brother Esau, and all his ill designs against him; and from being always under the bondage of Laban, into which he would be brought.

and will bring you again into this land: the land of Canaan, which was entailed on him and his seed for an inheritance; but, as he would now soon be out of it, and continue in another land for many years, as he did, which would make it look very unpromising that he and his seed should inherit it, this is said unto him.

for I will not leave you, until I have done [that] which I have spoken to you of; made good all his promises to him: and the sense is, not that he would then leave him when he had done so, but as not before, so never after; for God never does, nor never will, utterly forsake his people.