1 Chronicles 21:15
And God sent an angel unto Jerusalem to destroy it: and as he was destroying, the LORD beheld, and he repented him of the evil, and said to the angel that destroyed, It is enough, stay now thine hand. And the angel of the LORD stood by the threshingfloor of Ornan the Jebusite.
The verse concerns the punishment for David's sin in numbering the people by census. Seventy thousand had died by pestilence, and David and the elders of Israel mourned before God. God had sent an angel to destroy Jerusalem, then beheld the destroying and said it was enough, commanding the angel to stay his hand and sheath his sword.
The destruction was halted at the threshing floor of Ornan the Jebusite, where the angel of the Lord stood. There David confessed his sin and pleaded for the people, built an altar and offered sacrifices to stay the destroying angel. God accepted the offering by sending fire from heaven, turning aside the angel's sword.
God halted the destruction because He still loved His rebellious people. The sacrifice that turned aside the sword is a symbol of the Saviour's sacrifice and mediation for guilty people. One angel caused the terrible destruction, exercising the great destructive power that holy angels exercise when God commands.
The same destructive power will be exercised by evil angels when God permits. God's judgments do not come directly from Him but by withdrawal of protection, so that after warnings, counsels and reproofs are repeatedly refused He no longer commissions His angels to prevent Satan's attacks. Those thus left beyond His protection are left to be entangled and destroyed by Satan at sea and on land.