Malachi 3:1
1 “Behold*, I am about to send my messenger, who will clear the way before me. Indeed, the Lord you are seeking will suddenly come to his temple, and the messenger of the covenant, whom you long for, is certainly coming,” says the Lord of Heaven’s Armies. 2 Who can endure the day of his coming? Who can keep standing when he appears? For he will be like a refiner’s fire, like a launderer’s soap. 3 He will act like a refiner and purifier of silver and will cleanse the Levites and refine them like gold and silver. Then they will offer the Lord a proper offering.
Luke 1:31
29 But she was greatly troubled by his words and began to wonder about the meaning of this greeting. 30 So the angel said to her, “Do not be afraid, Mary, for you have found favor with God! 31 Behold100: You will become pregnant and give birth to a son, and you will name him Jesus. 32 He will be great and will be called the Son of the Most High, and the Lord God will give him the throne of his father David. 33 He will reign over the house of Jacob forever, and his kingdom will never end.”
Notes and References
"... There are some other simple allusions to Malachi in Luke. One of them is the Greek word (behold). Though the Greek word (behold) often occurs in Luke, it is especially used to emphasize John's birth (1:20) and Jesus' birth (1:31, 35). It is reminiscent of the Hebrew word (behold) which is twice used in Malachi 3:1, linked with two different eschatological figures' arrival. In light of the study of the relationship between Malachi and Luke, Luke must have had in his mind Malachi's eschatological figures - Elijah and Ha Adon - when he recorded John's and Jesus' birth. The citation in Luke 6:46 may be an allusion to Malachi 1:6 perhaps based upon the form and spirit of the rhetorical question posed by Jesus. Doble surmises that the Coming One may be suggested in Luke 7:16, and he seems to link the Coming One concept to Malachi‘s eschatological Elijah ..."
Lee, Paul Byeong Malachi's Eschatological Figures' Arrival Motif in the Gospel of Luke and its Relation to other Gospels (pp. 250-251) University of Pretoria, 2010