1 Nephi 20

First of all, I mentioned yesterday that I would look for testimonies of the Savior in the writings of Isaiah.  The first writings of Nephi were of what we now know as Isaiah 48 where Isaiah testifies -

"...I the Lord, yea, I have spoken; yea, I have called him to declare, I have brought him, and he shall make his way prosperous.
16 Come ye near unto me; I have not spoken in secret; from the beginning, from the time that it was declared have I spoken; and the Lord God, and his Spirit, hath sent me.
17 And thus saith the Lord, thy Redeemer, the Holy One of Israel; I have sent him, the Lord thy God who teacheth thee to profit, who leadeth thee by the way thou shouldst go, hath done it."  (Book of Mormon | 1 Nephi 20:15 - 17)

In my mind, in this writing of Isaiah, he explains over and over, that the Lord had provided revelations and prophecies, even concerning matters that were not current, such that when they happened, there is no question that this came from the Lord. Isaiah writes -

"Thou hast seen and heard all this; and will ye not declare them?  And that I have showed thee new things from this time, even hidden things, and thou didst not know them.
7 They are created now, and not from the beginning, even before the day when thou heardest them not they were declared unto thee, lest thou shouldst say—Behold I knew them.
8 Yea, and thou heardest not; yea, thou knewest not; yea, from that time thine ear was not opened; for I knew that thou wouldst deal very treacherously, and wast called a transgressor from the womb." (Book of Mormon | 1 Nephi 20:6 - 8)

This same truth is evident today as prophets, seers, and revelators provided "The Family: a Proclamation to the World".