Taken from a work (Quæs. et Resp. ad Othod.) ascribed to Justin Martyr, but certainly written after the Nicene Council. It is evident that this is not an exact quotation from Irenæus, but a summary of his words. The “Sunday” here referred to must be Easter Sunday. Massuet’s emendation of the text has been adopted, ἐπ’ αὐτοῦ for ἐπ’ αὐτῶν.