Charles Ellicott Commentary Romans 9:12

"it was said unto her, The elder shall serve the younger." — Romans 9:12 (ASV)

The elder shall serve the younger.—The margin gives as an alternative rendering, “the greater shall serve the lesser.” The quotation is taken from the LXX, in which there is the same ambiguity.

This ambiguity also appears to exist in the Hebrew, where it is a disputed question whether the words refer to age or to the comparative strength of the two peoples. In either case, it is the nations that should spring from Esau and Jacob that are meant.