Literally, the man, whoever he may be, that comes before them.
Before it hear him (ἐὰν μὴ ἀκούσῃ παρ' αὐτοῦ)
Rev., more correctly, except it first hear. Hear him, is an inadequate rendering of παρ' αὐτοῦ, which is, as Rev., from himself; παρά, implying from beside, i.e., from his side of the case.