Moses 3

As the Lord completed the six creative periods, He tells us of the seventh -

"...on the seventh day I, God, ended my work, and all things which I had made; and I rested on the seventh day from all my work, and all things which I had made were finished, and I, God, saw that they were good;
3 And I, God, blessed the seventh day, and sanctified it; because that in it I had rested from all my work which I, God, had created and made." (Pearl of Great Price Moses 3:2 - 3)

And then is seems He steps back and recounts -

"And now, behold, I say unto you, that these are the generations of the heaven and of the earth, when they were created, in the day that I, the Lord God, made the heaven and the earth..." (Pearl of Great Price Moses 3:4)

And then He seems to recounts even earlier events -

"And every plant of the field before it was in the earth, and every herb of the field before it grew. For I, the Lord God, created all things, of which I have spoken, spiritually, before they were naturally upon the face of the earth. For I, the Lord God, had not caused it to rain upon the face of the earth. And I, the Lord God, had created all the children of men; and not yet a man to till the ground; for in heaven created I them; and there was not yet flesh upon the earth, neither in the water, neither in the air..." (Pearl of Great Price Moses 3:5)

This single thought or remembrance reveals that all things were "spirits" or created as spirits in the presence of God before the seven creative periods. President Joseph Fielding Smith answered -

"The Lord informed Abraham that he had chosen rulers from among the intelligences that were organized, to be given in various capacities down the ages; and Abraham was one of these who was so chosen [see Abraham 3:22–23].

It is reasonable to believe that in the beginning, before the earth was prepared, the Lord would have all things organized from the beginning to the end of time. It is written in the scriptures: ‘Thus the heavens and the earth were finished, and all the hosts of them.’ This is equivalent to the Lord’s saying that everything was in preparation to be placed on the earth in its due course when mankind should be placed upon it." (Answers to Gospel Questions, comp., Joseph Fielding Smith Jr., 5 vols. [1957–66], 5:182)

He also explained -

"There is no account of the creation of man or other forms of life when they were created as spirits. There is just the simple statement that they were so created before the physical creation. The statements in Moses 3:5 and Genesis 2:5 are interpolations [parenthetical explanations] thrown into the account of the physical creation, explaining that all things were first created in the spirit existence in heaven before they were placed upon this earth.

We were all created untold ages before we were placed on this earth. We discover from Abraham 3:22–28, that it was before the earth was formed that the plan of salvation was presented to the spirits, or ‘intelligences.’ This being true, then man, animals and plants were not created in the spirit at the time of the creation of the earth, but long before." (Doctrines of Salvation, 1:75–76)