'Seal Up' in the Bible

O set me as a seal upon thine heart, and as a seal upon thine arm: for love is mighty as the death, and jealousy as the hell. Her coals are of fire, and a very flame of the LORD:

And when the seven thunders had spoken their voices, I was about to write. And I heard a voice from heaven saying unto me, "Seal up those things which the seven thunders spake, and write them not."