1 Chronicles 21:20
And Ornan turned back, and saw the angel; and his four sons with him hid themselves. Now Ornan was threshing wheat. And Ornan turned back, and saw the angel; and his four sons with him hid themselves. Now Ornan was threshing wheat.
Ornan was at his threshing floor threshing wheat when he saw the angel, while his four sons with him hid themselves. He offered David the threshing floor for an altar, together with what was needed for the sacrifice. That threshing floor was the spot where the temple was later built. That spot had long been regarded as a consecrated place where worshipers of Jehovah met God and renewed vows of allegiance. It was the same place where Abraham showed willingness to sacrifice his only son in obedience to Jehovah's command, and where God renewed with Abraham the covenant of blessing, including the messianic promise of deliverance through the sacrifice of the Son of the Most High.
David offered burnt offerings and peace offerings there to stay the avenging sword of the destroying angel, and God answered him by fire from heaven. The sacrifice offered there, in its flames, turned aside the destroying angel's sword. The event is a fitting symbol pointing to the Saviour's sacrifice and mediation for guilty people.