Charles Ellicott Commentary 1 Chronicles 21:26

"And David built there an altar unto Jehovah, and offered burnt-offerings and peace-offerings, and called upon Jehovah; and he answered him from heaven by fire upon the altar of burnt-offering." — 1 Chronicles 21:26 (ASV)

And David built ... peace offerings. —Word for word as in Samuel.

And called upon the Lord. —Not in Samuel, where the narrative ends with the words, “And the Lord was entreated for the land, and the plague was stayed from Israel.”

From heaven by fire (with the fire from the heavens). —The Divine inauguration of the new altar and place of sacrifice. (1 Kings 18:24; 1 Kings 18:38—Elijah’s sacrifice; 2 Chronicles 7:1.) Also a sign that David’s prayer was heard.