Note the form of this promise. God does not say, "And when you shall look upon the bow, and you shall remember My covenant, then I will not destroy the earth," but it is gloriously put, not upon our memory, which is fickle and frail, but upon God's memory, which is infinite and immutable. "When . . . the bow is seen in the clouds, I will remember my covenant." It is not my remembering God—it is God's remembering me that is the ground of my safety; it is not my laying hold of His covenant, but His covenant's laying hold on me. Glory be to God!
The ramparts of salvation are secured by divine power, and even the minor towers, which we could imagine being left to man, are guarded by almighty strength. Even the remembrance of the covenant is not left to our memories, for we might forget; but our Lord cannot forget the names of those whom He has graven on the palms of His hands. It is with us as it was with Israel in Egypt; the blood was upon the lintel and the two side-posts, but the Lord did not say, "When you see the blood I will pass over you," but "When I see the blood I will pass over you."
My looking to Jesus brings me joy and peace, but it is God's looking to Jesus that secures my salvation and that of all His elect, since it is impossible for our God to look at Christ, our bleeding Surety, and then to be angry with us for sins already punished in Him. It is not left with us even to be saved by remembering the covenant. There is not a single thread of human effort in this fabric. It is not of man, neither by man, but of the Lord alone. We should remember the covenant, and we shall do it, through divine grace; but the hinge of our safety does not hang there—it is God's remembering us, not our remembering Him; and hence the covenant is an everlasting covenant.