Abraham 3

 Abraham shares that early in his life, that - 

"...I, Abraham, had the Urim and Thummim, which the Lord my God had given unto me, in Ur of the Chaldees..."  Abraham 3:1

"And the Lord said unto me, by the Urim and Thummim, that Kolob 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. This is the reckoning of the Lord’s time, according to the reckoning of Kolob."  Abraham 3:4

I find it interesting that it was through the Urim and Thummim that the Lord taught Abraham great truths concerning the universe, which we learn later that he taught Pharaoh.