Malachi (măl'a-ki), messenger of Jehovah. The last of the prophets of the Old Testament, and called "the seal" because his prophecies form the closing book of the canon of the Old Testament. Of his personal life nothing is known but what can be gleaned from his book. He flourished after the captivity, later than Haggai and Zechariah, at a time when the temple was completed, and was probably a contemporary of Nehemiah, b.c. 433. His prophecies are at once denunciatory of prevailing vices, and close with a prophecy of the coming of Messiah, and foretells that Elijah will return as a forerunner of Messiah—a prediction which found its striking fulfilment by the mission of John the Baptist Malachi 4:5; Luke 1:17; Matthew 11:14; Matthew 17:12.