Kolob, signifying the first creation, nearest to the celestial, or the residence of God. First in government, the last pertaining to the measurement of time. The measurement according to celestial time, which celestial time signifies one day to a cubit. One day in Kolob is equal to a thousand years according to the measurement of this earth, which is called by the Egyptians Jah-oh-eh. Pearl of Great Price, Abraham chapter 3, Joseph Smith.
The book of Abraham states that God's physical dominion (throne) is located near a star called Kolob (Abraham 3:2-3). While it might seem reasonable to suppose that this refers to some distinguishing feature of the universe, all efforts to identify it are speculative and not authoritative. Wherever Kolob is located, its purpose is to "govern" all planets that are of the same "order" as the Earth (Abraham 3:9). Since Abraham says no more than that, it is not clear whether he is speaking physically, metaphorically, or allegorically. Thus, "to govern" might mean a physical bonding as with gravity, while "order" could conceivably mean planets similar to the Earth in size, or planets in the same region of this galaxy or even in the entire Milky Way galaxy. Kolob was also said by the Egyptians to provide the light for all stars, including that for our sun (Abr. Facsimile 2). Even so, Latter-day Saints have made no definitive comment on the meaning of these passages. Encyclopedia of Mormonism; Daniel H. Ludlow (editor), 1992.
Some of this revelation has already taken place. For instance: We know that on Kolob, where the Lord's time prevails, a day is 1,000 years of our time. (Abraham 3:4; 2 Peter 3:8.) Thus it is that the time element in the creation of this earth was reckoned "after the Lord's time, which was after the time of Kolob; for as yet the Gods had not appointed unto Adam his reckoning." (Abraham 5:13) Mormon Doctrine; Time, Bruce R. McConkie, 1966.
Another extremely important doctrine revealed to Abraham and recorded in this story, is in relation to the universe and astronomy in general. By means of the Urim and Thummim, Abraham had revealed to him many great secrets concerning the governing planets in our universe. Not only did he discover this by Urim and Thummim, but the Lord talked with him in a personal appearance. The Lord showed to him the stars, and among them many that were very great. These were great not only in size, but also in their importance as governing worlds. Among these, one named Kolob was revealed as the great governing star of our universe. This great star, "was after the manner of the Lord, according to its times and seasons in the revolutions thereof; that one revolution was a day unto the Lord, after his manner of reckoning, it being one thousand years according to the time appointed unto that whereon thou standest, (the earth.) This is the reckoning of the Lord's time according to the reckoning of Kolob." Church History and Modern Revelation; Joseph Fielding Smith, 1946.