Thus; so called by the dealers of drugs in Egypt from thur, or thor, the name of a harbour in the north bay of the Red Sea, near Mount Sinai; thereby distinguishing it from the gum arabic, which is brought from Suez, another port in the Red Sea, not far from Cairo. It differs also in being more pellucid and white. It burns with a bright and strong flame, not easily extinguished. It was used in the temple service as an emblem of prayer, Psalms 141:2; Revelation 8:3-4 . Authors give it, or the best sort of it, the epithets white, pure, pellucid; and so it may have some connection with a word, derived from the same root, signifying unstained, clear, and so applied to moral whiteness and purity, Psalms 51:7; Daniel 12:10 . This gum is said to distil from incisions made in the tree during the heat of summer. What the form of the tree is which yields it, we do not certainly know. Pliny one while says, it is like a pear tree, another, that it is like a mastic tree; then, that it is like the laurel; and, in fine, that it is a kind of turpentine tree. It has been said to grow only in the country of the Sabeans, a people in Arabia Felix; and Theophrastus and Pliny affirm that it is found in Arabia. Dioscorides, however, mentions an Indian as well as an Arabian frankincense. At the present day it is brought from the East Indies, but not of so good a quality as that from Arabia. The "sweet incense," mentioned Exodus 30:7 , and elsewhere, was a compound of several drugs, agreeably to the direction in the thirty-fourth verse. To offer incense was an office peculiar to the priests. They went twice a day into the holy place; namely, morning and evening, to burn incense there. Upon the great, day of expiation, the high priest took incense, or perfume, pounded and ready for being put into the censer, and threw it upon the fire the moment he went into the sanctuary. One reason of this was, that so the smoke which rose from the censer might prevent his looking with too much curiosity on the ark and mercy-seat. God threatened him with death upon failing to perform this ceremony, Leviticus 16:13 . Generally incense is to be considered as an emblem of the "prayers of the saints," and is so used by the sacred writers.