פּירוש אויף בראשית 7:1

ראיתי צדיק [THEE] HAVE I SEEN RIGHTEOUS — It does not say “righteous and wholehearted” (as it does at the beginning of the Sedrah); hence we may infer that only a part of a man’s good qualities should be enumerated in his presence (since here God is speaking to Noah and calls him only “righteous”), but that in his absence the whole of his good qualities may be told (since when the Torah speaks about him in the earlier passage it calls him “righteous and wholehearted”) (Eruvin 18b).

ויאמר ה׳, “The Lord said:” The previous time G-d had been reported as speaking to Noach, (6,13) it was His attribute of Justice speaking, whereas here it refers to His attribute of Mercy addressing him.

AND THE ETERNAL SAID TO NOAH. G-d informed Noah that with the attribute of mercy [as indicated by the use of the Tetragrammaton, “the Eternal,”] He will save him and his family and that He will give life to their seed for all generations. This is the meaning of the phrase, to keep seed alive upon the face of all the earth.⁷¹Verse 3. At first He said, to keep them alive with thee;⁷²Above, 6:19. but now with the attribute of mercy He hinted to him concerning the sacrifice to inform him that he will have regard for his offering and that by the merit of his offering, the world will exist, never again to be cut off by the waters of the flood.⁷³See further, 9:11. This is why the Tetragrammaton is mentioned here for in all matters concerning the sacrifices, Scripture does not mention Elokim (G-d), as I will elucidate when I reach there⁷⁴See Ramban, Leviticus 1:9. with the help of G-d.