See also: Abraham 3:2-16
Abraham learned that wherever there are two stars one will be greater than the other, and that there are other stars greater than those two, until Kolob, which is the greatest of all. He learned that it is not size that makes one star or planet greater than another, but rather its proximity to Kolob. So it is with the children of God – their greatness and glory will depend upon their proximity to the Creator, Jesus Christ, who is “nearest unto the throne of God,” “the great one,” “the first creation,” and is “set to govern all those which belong to the same order.” Thus the great star, Kolob, is a symbol of Jesus Christ. — The Pearl of Great Price Student Manual, p. 37
When this earth was created, it was not according to our present time, but it was created according to Kolob’s time, for the Lord has said it was created on celestial time which is Kolob’s time. Then he revealed to Abraham that Adam was subject to Kolob’s time before his transgression. (Joseph Fielding Smith, Doctrines of Salvation, 1:79)
This helps us understand the Lord’s warning to Adam and Eve regarding their partaking of the fruit of the tree of knowledge of good and evil: “In the day thou eatest thereof thou shalt surely die” (Moses 3:17; see also Genesis 2:17; Abraham 5:13). After Adam and Eve partook of the fruit, they did not die physically within a 24-hour period, as we now measure a day. Adam did, however, die within the period of one Kolob day (one thousand earth years, as measured after the Fall; see Abraham 3:4; 2 Peter 3:8). Moses 6:12 indicates that Adam died 930 years after the Fall. — The Pearl of Great Price Student Manual, p. 41
President Joseph Fielding Smith wrote: “The Lord made known to him [Abraham] the following facts: That Kolob is the first creation, and is nearest to the celestial, or the residence of God. It is the first in government, the last pertaining to the measurement of time. This measurement is according to celestial time. One day in Kolob is equal to a thousand years according to the measurement of this earth, which by the Egyptians was called Jah-oh-eh. Oliblish, so called by the Egyptians, stands next to Kolob in the grand governing creation near the celestial, or place where God resides. This great star is also a governing star and is equal to Kolob in its revolutions and in its measuring of time. Other grand governing stars were also revealed to Abraham” (Man: His Origin and Destiny , 461).
Abraham learned that, like Kolob, there were other stars that were “very great,” and that these great stars were governing stars (see Abraham 3:2-3). The Lord taught Abraham about “the set time of all the stars” (v. 10; see also vv. 4-9). Abraham also learned that there are other governing stars located nearer to Kolob and that they rotate more slowly, or “longer,” than many other stars (but not more slowly than Kolob).
The Lord’s teachings about stars and planets helped Abraham understand more about this earth and its relationship to Kolob. For example, he taught Abraham that one day on Kolob was equal to one thousand years of time on our earth (see Abraham 3:4). — Pearl of Great Price Student Manual, p. 36