Genesis 6:18

Either,

1. My promise to preserve thee and thine, both till the flood and in it, notwithstanding all the scoffs and threats of the wicked world against thee all the time of thy preaching and building of the ark. The word covenant being here understood, not of a mutual compact or agreement, but of a single and gracious promise, as it is also used Numbers 18:19, Numbers 25:12, and in other places. Which promise, though only here mentioned, was doubtless made before, as may easily be gathered, both from these words and some foregoing passages, and from the need which Noah had of such a support and encouragement during all the time of his ministry. Or,

2. My covenant concerning the sending of the promised Seed, and the redemption of mankind by the Messias, who shall come out of thy loins, and therefore thou shalt be preserved.