Jesus said, I am the light of the world; he that followeth Me shall not walk in darkness, but shall have the light of life (John 8:12). As long as I am in the world I am the light of the world (John 9:5). Jesus said, Yet a little while is the light with you. Walk while ye have the light, lest darkness overtake you. While ye have the light believe in the light, that ye may be sons of light. I have come a light into the world, that whosoever believeth in Me may not abide in darkness (John 12:35, 36, 46). Light has come into the world, but men have loved the darkness rather than the light (John 3:19).

John says of the Lord:

This is the true light which lighteneth every man (John 1:9). The people that sit in darkness have seen a great light, and to them that were sitting in the shadow of death light is sprung up (Matt. 4:16). I will give thee for a covenant of the people, for a light of the Gentiles (Isa. 13:6). I have established Thee for a light of the Gentiles that Thou mayest be My salvation unto the end of the earth (Isa. 19:6). The nations of them that are saved shall walk in His light (Apoc. 21:24). Send out Thy light and Thy truth; let them lead me (Psalm 43:3).

In these and other passages the Lord is called light from Divine truth, which is from Him; and the truth itself is likewise called light. As light in the heavens is from the Lord as a sun, so when He was transfigured before Peter, James, and John:

His face did shine as the sun, and His raiment was white as the light (Matt. 17:2). And His garments became shining, exceeding white as snow, so as no fuller on earth can whiten them (Mark 9:3; Matt. 17:2).

The Lord's garments had this appearance because they represented Divine truth which is from Him in the heavens, "garments" also in the Word signifying truths,# consequently it is said in David:

O Jehovah, Thou coverest Thyself with light as with a garment (Psalm 104:2). # In the Word "garments" signify truths, because truths clothe good (n. 1073, 2576, 5248, 5319, 5954, 9216, 9952, 10536). The Lord's garments when He was transfigured signified Divine truth going forth from His Divine love (n. 9212, 9216).