An Etymological Dictionary of the German Language/Vesper
Vesper, f., ‘vespers, evening,’ from the equiv. MidHG. vësper, OHG. vëspera, f., which was adopted contemporaneously with monastic institutions (comp. Mette and None), from Lat. vespera (whence also Ital. vespro, Fr. vêpre). The primit. kinship of the Lat. with the MidHG. and OHG. word is inconceivable, because the correspondence of Lat. v with OHG. v (f) is found only in OHG. loan-words (see Vogt and Käfig).