We might ponder what those three words mean. Right in the next phrase, Lehi says that the Savior will lay down his life according to the flesh. Those are his merits, and he taketh it up again by the power of the spirit that he may bring to pass the resurrection of the dead being the first that should rise. That’s certainly his suffering, his overcoming of death which gives him the power, gives him the merits, the strength, the worthiness, to be able to then become the first-fruits unto God inasmuch as he shall make intercession for all the children of men and there I see the mercy, the intercession which allows for further time for repentance to take place, that they that believe in him shall be saved. And that’s the grace that operates to allow us to be saved. And then, because of the intercession for all, all men come unto God and must stand in the presence him to be judged according to the truth and holiness which is in him. We will not only be judged according to our works, but we will be judged in accordance with the mercy, truth, and holiness of God as well.
Intercession is a word relating to how the priests, particularly the high priest in the temple of Israel, would make an offering, an atoning sacrifice which would act as an intercessory sacrifice—one person doing it for the benefit of the whole nation—and this what Lehi is referencing. Christ will make himself an intercessor, offering himself as a sacrifice for all the children of men. That is classic temple imagery.