'Unloose' in the Bible

And he was preaching, saying, “After me comes He who is mightier [more powerful, more noble] than I, and I am not worthy to stoop down and untie the straps of His sandals [even as His slave].

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].”