John 1:25-27

They asked him, “Why then are you baptizing, if you are not the Christ, nor Elijah, nor the Prophet?” John answered them, “I baptize [only] in water, but among you there stands One whom you do not recognize and of whom you know nothing. [Mal 3:1] It is He [the preeminent One] who comes after me, the strap of whose sandal I am not worthy to untie [even as His slave].”