This can be stated in active form. Alternate translation: "what the Lord spoke long ago through the prophets" (See: [[rc://en/ta/man/jit/figs-activepassive]])
Here "he" refers to Jesus. The prophets before the time of Jesus would have referred to him as the Messiah or the Christ. Alternate translation: "people would say that the Christ is a Nazarene" (See: [[rc://en/ta/man/jit/translate-names]])