Malachi 3:1; Malachi 4:5

1 "Look! I am sending my messenger to clear the way before me; and the Lord, whom you seek, will suddenly come to his temple. Yes, the messenger of the covenant, in whom you take such delight - look! Here he comes," says ADONAI-Tzva'ot.

5 Look, I will send to you Eliyahu the prophet before the coming of the great and terrible Day of ADONAI.