Hastings' Dictionary of the Bible (1898)
IN'CENSE. Ex 30:8. This was a compound of frankincense and other gums or spices, the materials and manufacture of which are particularly prescribed. Ex 30:34-36. See Frankincense. It was the business of the priest to burn it morning and evening upon an altar specially erected for this purpose, and thence called the altar of incense. The preparation of it for common use was positively forbidden; neither could any other composition be offered as incense on this altar, nor could this be offered by any but the priest.
The offering of incense was symbolical of prayer, or, as some think, rather of that which makes prayer acceptable — the intercession of Christ. See Altar, Censer, Frankincense. Incense was considered sacred, and might be offered by the priest only. When King Uzziah attempted to use it in the temple, he was struck with leprosy. 2 Chr 26:16-21. Incense was offered to heathen deities and idols, Jer 11:12, 1 Kgs 11:17, and the angels offer it in heaven. Rev 8:3.