Albert Barnes 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)

He answered him from heaven by fire. This fact is not mentioned by the author of Samuel, because his purpose was to give an account of David’s sin, its punishment, and the circumstances that brought that punishment to a close, not to connect those events with anything further in the history.

With the writer of Chronicles, the case is different. He likely would have omitted the entire narrative, as he did David’s sin in the matter of Uriah, except for its connection with establishing the temple site (1 Chronicles 22:1).

It was undoubtedly mainly the fact that God answered him by fire from heaven on this altar that determined David, and Solomon after him, to build the temple on that consecrated spot.