Also: God says, “Behold, I will send you Elijah the prophet before the coming of the great and dreadful day of the LORD. And he will turn the hearts of the fathers to the children, and the hearts of the children to their fathers, lest I come and strike the earth with a curse” (Malachi 4:5,6).
These are the last words of God recorded by the last prophet, nothing more for four hundred years, unto John Baptist's ministry began, which John himself knew, and of which he quoted from Isaiah. I believe this is figuratively speaking of John, not of the literal coming of Elijah, which occurs in the midst of, not before, that great and terrible Day of The LORD (Rev. 8-11). With this prophecy from Isaiah, John Baptist, as a prophet, ended the centuries of God's silence (Is. 40:3-5).