Albert Barnes Commentary 2 Chronicles 2:4

"Behold, I am about to build a house for the name of Jehovah my God, to dedicate it to him, and to burn before him incense of sweet spices, and for the continual showbread, and for the burnt-offerings morning and evening, on the sabbaths, and on the new moons, and on the set feasts of Jehovah our God. This is [an ordinance] for ever to Israel." — 2 Chronicles 2:4 (ASV)

The symbolic meaning of “burning incense” is indicated in Revelation 8:3–4. Consulting cross-references for these verses is also helpful.

The solemn feasts were the three great annual festivals: the Passover, the Feast of Weeks (Pentecost), and the Feast of Tabernacles (Deuteronomy 16:1–17).