'Solemn' in the Bible

And God said, “This is the token (visible symbol, memorial) of the [solemn] covenant which I am making between Me and you and every living creature that is with you, for all future generations;

I set My rainbow in the clouds, and it shall be a sign of a covenant between Me and the earth.

and I will [compassionately] remember My covenant, which is between Me and you and every living creature of all flesh; and never again will the water become a flood to destroy all flesh.

And God said to Noah, “This [rainbow] is the sign of the covenant (solemn pledge, binding agreement) which I have established between Me and all living things on the earth.”

“I will establish My covenant (everlasting promise) between Me and you,And I will multiply you exceedingly [through your descendants].”

“As for Me, behold, My covenant is with you,And [as a result] you shall be the father of many nations.

I will establish My covenant between Me and you and your descendants after you throughout their generations for an everlasting covenant, to be God to you and to your descendants after you.

But God said, “No, Sarah your wife shall bear you a son indeed, and you shall name him Isaac (laughter); and I will establish My covenant with him for an everlasting covenant and with his descendants after him.