Thematic Bible: The seven thunders

and he called out in a loud voice, like a roaring lion. And when he shouted, the seven thunders responded to the voice [of the angel]. [Note: These "seven thunders" have not been previously mentioned]. And when the seven thunders spoke [words], I started to write down [what the voices said], but I heard a voice from heaven saying, "Seal up what the seven thunders have [just] said, and do not write them down."