David built an altar to the LORD there and sacrificed burnt offerings and fellowship offerings. He called on the LORD, and the LORD answered him with fire1 from heaven on the altar of burnt offering.
References for 1 Chronicles 21:26
Then the LORD spoke to the angel, and he put his sword back into its sheath.
At that time, when David saw that the LORD had answered him on the threshing floor of Araunah the Jebusite, he offered sacrifices there.
The tabernacle of the LORD, which Moses had made in the desert, and the altar of burnt offering were at that time on the high place at Gibeon.2
References for 1 Chronicles 21:29
But David could not go before it to inquire of God, because he was afraid of the sword of the angel of the LORD.