The Lord's messenger is like a refiner's fire (Mal 3:2)

Malachi prophesied in Jerusalem, probably in the fifth century BC.

Malachi first tells of God's love for Israel, then condemns the priests who have been unfaithful in their service and the people who have been unfaithful in marriage (Mal 1-2). The prophet announces that God will send a messenger to purify the people.   God promises to receive those who repent and to spare those who serve him. Elijah is the one whom God will send to reconcile parents and children before the day of the Lord (4:5-6). The New Testament applies this promise to John the Baptist (Luke 1:17).

Mal 4:5-6 - Coming of Elijah