Canon 17
About the fact that bigamists and fornicators cannot be clerics.
Anyone who has been married twice after baptism or who has taken a concubine cannot be a bishop, or a presbyter, or a deacon, or even belong to the list of the holy order.
Greek original
Ὁ δυσὶ γάμοις συμπλακείς μετὰ τὸ βάπτισμα, ἢ παλλακὴν κτησάμενος, οὐ δύναται εἶναι ἐπίσκοπος, ἢ πρεσβύτερος, ἢ διάκονος, ἢ ὅλως τοῦ καταλόγου τοῦ ἱερατικοῦ.
Parallel canons
Ап.18Трул.3Вас.12