John Calvin Commentary Genesis 35:14

"And Jacob set up a pillar in the place where he spake with him, a pillar of stone: and he poured out a drink-offering thereon, and poured oil thereon." — Genesis 35:14 (ASV)

And Jacob set up a pillar. Though it is possible that he may have again erected a sacred monument in memory of the second vision, I readily agree with the opinion of those who think that this refers to what had been done before. It is as if Moses were saying that this was the ancient temple of God, where Jacob had poured out his libation. For he had not been commanded to come there to live there, but so that a fresh view of the place might renew his faith in the ancient oracle and more fully confirm it.

We read elsewhere that altars were built by the holy fathers where they intended to remain longer, but their reason for doing so was different: for since Jacob had made a solemn vow in Bethel (on the condition that he would be brought back by the Lord in safety); thanksgiving is now required of him, after he has become bound by his vow, so that, being strengthened, he may continue on his journey.