the Lamb of God is the Son of the Eternal Father

“And the angel spake unto me saying: These last records, which thou hast see among the Gentiles shall establish the truth of the first (the Bible) which are of the twelve apostles of the Lamb, (The New Testament, which Nephi knew nothing about because Christ had not yet been born.) And shall make known the plain and precious things which have been taken away from them: (during the dark ages) and shall make known to all kindreds, tongues and people that the Lamb of God is the Son of the Eternal Father, and the Savior of the world, and that all men must come unto him, or they cannot be saved.” (1 Nephi 13:40)   Between 600 and 592 B.C.

I have added the words in parentheses for my clarification.