(Chapter 28, verse 19) And he called the name of that place Bethel, but previously its name was Luz. From what he had said above: How awesome is this place, it is nothing but the house of God, and this is the gate of heaven: now he gives the place a name, and he calls it Bethel, which means the house of God. The place was previously called Luz, which means nut or almond. Therefore, some foolishly think that the Hebrew word Ulam is the name of a city, when Ulam actually means previously. Therefore, the order of the reading is as follows: And he called the name of that place Bethel, and before it was called Luz, a city. All the ancient scriptures are full of the word 'ulam', or 'Elam', which signifies nothing else but before, or previously, or threshold, or gateposts.
[AD 420] Jerome on Genesis 28:19