Charles Ellicott Commentary Genesis 48:3

"And Jacob said unto Joseph, God Almighty appeared unto me at Luz in the land of Canaan, and blessed me," — Genesis 48:3 (ASV)

God Almighty. —Hebrew, El Shaddai. The act recorded in this chapter is grounded by Jacob on the promise made to him at Bethel on his return from Padan-aram; and it was under the old covenant name by which God had revealed Himself to Abram (Genesis 17:1) that he was there made the heir of the Abrahamic promises. (See Note on Genesis 35:11.)

Luz. —This use of the old name shows how very slowly the new titles of places, derived from incidents in the history of a small tribe, took the place of their native and original names. In a similar manner, in the recent exploration of Palestine, it has been found that the high-sounding titles given by the Seleucids and Romans to towns there have never been adopted by the local inhabitants, who still call them by their old names.