Exodus 12:29
27 then you will say, ‘It is the sacrifice of the Lord’s Passover, when he passed over the houses of the Israelites in Egypt, when he struck Egypt and delivered our households.’” The people bowed down low to the ground, 28 and the Israelites went away and did exactly as the Lord had commanded Moses and Aaron. 29 It happened at midnight—the Lord attacked all the firstborn in the land of Egypt, from the firstborn of Pharaoh who sat on his throne to the firstborn of the captive who was in the prison, and all the firstborn of the cattle. 30 Pharaoh got up in the night, along with all his servants and all Egypt, and there was a great cry in Egypt, for there was no house in which there was not someone dead. 31 Pharaoh summoned Moses and Aaron in the night and said, “Get up, get out from among my people, both you and the Israelites! Go, serve the Lord as you have requested!
2 Kings 19:35
33 He will go back the way he came. He will not enter this city,” says the Lord. 34 “‘I will shield this city and rescue it for the sake of my reputation and because of my promise to David my servant.’” 35 That very night the angel of the Lord went out and killed 185,000 in the Assyrian camp. When they got up early the next morning, there were all the corpses. 36 So King Sennacherib of Assyria broke camp and went on his way. He went home and stayed in Nineveh. 37 One day, as he was worshiping in the temple of his god Nisroch, his sons Adrammelech and Sharezer struck him down with the sword. They escaped to the land of Ararat; his son Esarhaddon replaced him as king.
Notes and References
"... In the Old Testament supernatural envoys (םיכאלמ) usually delivered messages to specific audiences, or went before people to protect them and destroy or threaten the enemies of YHWH. (Compare Numbers 22:22; 2 Samuel 24:16; 2 Kings 19:35; 1 Chronicles 21:15; Psalm 35:5-6) In the exodus narrative, envoys of YHWH appear several times. First, an envoy appeared to Moses at Sinai to speak YHWH’s words to him (Exodus 3:2). This envoy played no military role, but revealed YHWH to Moses. Second, a destroyer (תיחשמ) assisted YHWH during the tenth plague, fulfilling an earlier threat to kill the first-born son of Pharaoh (Exodus 4:23). Unlike the previous plagues, YHWH took on the task of killing the first-born of Egypt by going through Egypt (11:4; 12:12, 23) and striking and killing the Egyptian first-born (12:12, 23, 27, 29; 13:15), but he promised to protect from the destroyer the Israelites who had put blood on their doorframes (Exodus 12:23). Even though YHWH executed this task through the destroyer, his close identification with the supernatural envoy allows him to describe these actions with first person verbs ..."
Trimm, Charlie "YHWH Fights for Them!": The Divine Warrior in the Exodus Narrative (pp. 62-63) Gorgias Press, 2014