The greater of earth’s two heavenly luminaries; the earth’s principal created source of energy, without which life on earth would be impossible. The sun (Heb., sheʹmesh; Gr., heʹli·os), together with the moon, also serves man as a timepiece for measuring the seasons, days, and years. (Ge 1:14-18) The sun is a gift from “the Father of the celestial lights,” who makes it shine upon all alike, the wicked and the good. (Jas 1:17; Jer 31:35; Mt 5:45) Certainly the sun can be said to praise its magnificent Creator.​—Ps 148:3.

The sun is a star about 1,392,000 km (865,000 mi) in diameter, more than a hundred times the diameter of the earth, and more than a million  times the volume of the earth. Its average distance from the earth is over 149,600,000 km (93,000,000 mi). The surface temperature of the sun is said to be about 6,000° C. (11,000° F.). But because of its great distance from the earth, less than one billionth of its radiant energy reaches the earth, an amount, however, fully sufficient to provide ideal climatic conditions that make vegetable and animal life on earth possible.​—De 33:14; 2Sa 23:4.

Jehovah and Christ More Brilliant. The surpassing brilliance and glory of Jehovah, the sun’s Creator, is indicated by the fact that his resurrected Son, in a partial revelation to Saul, presented a light “beyond the brilliance of the sun.” (Ac 26:13) In the holy city, New Jerusalem, there will be no need for the sun as light, for “the glory of God” will light it up and “its lamp” will be the Lamb.​—Re 21:2, 23; 22:5.

God’s Power Over the Sunlight. The day Jesus was fastened to a torture stake, from the sixth hour (11:00 a.m. to 12 noon) until the ninth hour (2:00 to 3:00 p.m.) a darkness fell over all the land. (Mt 27:45; Mr 15:33) Luke’s account adds that the darkness fell “because the sunlight failed.” (Lu 23:44, 45) This could not have been due to an eclipse of the sun by the moon, as some think, for the darkness occurred at Passover time, which was always the time of full moon. It is about two weeks later that the moon is new, that is, in the same direction as the sun from the earth (the time when solar eclipses occur).

Long before this occasion, Jehovah had demonstrated his ability to shut out the sunlight. This was when the Israelites were down in Egypt. During the ninth plague thick darkness enveloped the Egyptians with darkness that could “be felt.” It lasted for three days, longer than any eclipse of the sun by the moon. Also, in the nearby land of Goshen, the Israelites at the same time enjoyed light.​—Ex 10:21-23.

In answering his disciples’ question as to his presence and the conclusion of the system of things, Jesus predicted unusual darkening of the sun.​—Mt 24:3, 29; Mr 13:24; Lu 21:25; compare Isa 13:10; Joe 2:10, 31; 3:15; Ac 2:20; see HEAVEN (Darkening of the Heavens).

Time and Direction. Time was often designated by references to the sun’s position. (Ge 15:12, 17; 32:31; De 16:6; Jos 8:29; Jg 9:33; 1Sa 11:9) Direction was similarly indicated. (De 11:30; Jos 12:1) “Under the sun” was used to mean “anywhere (or everywhere) on earth.” (Ec 5:18; 9:11) “Under the eyes” of the sun or “in front of the sun” meant “in the open, for all to see.”​—2Sa 12:11, 12.

Figurative Use. Jehovah God is called “a sun and a shield,” not that he is a nature god, but that he is the Source of light, life, and energy. (Ps 84:11) He is also spoken of as a shade to his people, so that “the sun itself will not strike” them. Here that which brings calamity is likened to the sun’s heat. (Ps 121:6, 7) Persecution (Mt 13:5, 6, 20, 21) and divine anger are sometimes represented by the scorching heat of the sun.​—Re 7:16.

Jehovah likened rebellious Jerusalem to a woman who had borne seven sons, describing the judgment coming upon her by the figurative expression, “Her sun has set while it is yet day,” that is, before the evening of her life was reached she would experience calamity. This was fulfilled when Babylon destroyed Jerusalem. (Jer 15:9) In similar vein, Micah prophesied against the prophets misleading Israel: “The sun will certainly set upon the prophets, and the day must get dark upon them.” (Mic 3:6; compare Am 8:9.) Jehovah’s Kingdom rule is pictured as so bright that it can be said, in comparison: “The full moon has become abashed, and the glowing sun has become ashamed.” (Isa 24:23) Jesus said that, at the conclusion of the system of things, “the righteous ones will shine as brightly as the sun in the kingdom of their Father.”​—Mt 13:39, 43; compare Da 12:3; see LIGHT.

Sun Worship. During King Josiah’s cleansing work, “he put out of business the foreign-god priests, whom the kings of Judah had put in that they might make sacrificial smoke . . . to the sun and to the moon.” “Further, he caused the horses that the kings of Judah had given to the sun to cease from entering the house of Jehovah . . . and the chariots of the sun he burned in the fire.” (2Ki 23:5, 11) Later, the prophet Ezekiel, down in Babylon, was given a vision of Jehovah’s temple at Jerusalem. There he saw about 25 men between the porch and the altar, “bowing down to the east, to the sun.” (Eze 8:16) Such disgusting practices brought Jerusalem to ruin in 607 B.C.E., when Jehovah’s instrument Nebuchadnezzar destroyed the city and the temple.​—Jer 52:12-14.

Shadow That Went Ten Steps Back. The use of sundials extends back beyond the eighth century B.C.E. in both Babylon and Egypt. However, the Hebrew word ma·ʽalohthʹ, translated “dial” at 2 Kings 20:11 and Isaiah 38:8, in the King James Version, literally means “steps” (NW) or “degrees,” as is indicated in the King James Version marginal readings on these verses. This  word is also used in the superscriptions of the 15 ‘Songs of the Ascents,’ Psalms 120 to 134.

In the scriptures mentioned, at 2 Kings 20:8-11 and Isaiah 38:4-8, the account is related of the portent God gave sick King Hezekiah in answer to Isaiah’s prayer. It consisted of causing a shadow that had gradually fallen to reverse its direction and go back up ten steps. This could refer to the steps, or degrees, of a dial for measuring time, and it is not impossible that Hezekiah’s father possessed such a sundial, even obtaining it from Babylon. However, the Jewish historian Josephus in discussing the account speaks of these steps of Ahaz as being “in the house,” apparently indicating that they formed part of a stairway. (Jewish Antiquities, X, 29 [ii, 1]) There may have been a column placed alongside the stairs to receive the sun’s rays and cause a shadow to extend gradually along the steps and serve as a measurement of time.

The miracle performed could have involved the relationship between earth and sun, and if so, it could have been similar to the miracle recorded at Joshua 10:12-14. (See POWER, POWERFUL WORKS [Sun and moon stand still].) It appears that this portent had far-reaching effects, inasmuch as 2 Chronicles 32:24, 31 shows that messengers were sent from Babylon to Jerusalem to inquire about it.