This word is explained by what follows. He believed (at length) that Jesus was risen; for up to this time (οὐδεÌπω) he, with his fellow-disciple (plural, ἠÌͅδεισαν) knew not, etc. The singular number, he believed, as Meyer profoundly remarks, “only satisfies the never-to-be-forgotten personal experience of that moment, though it does not exclude the contemporaneous faith of Peter also.†On knew (ἠÌͅδεισαν), see on Joh 2:24.