An Etymological Dictionary of the German Language/Ehe
Ehe, f., ‘marriage, wedlock, matrimony,’ from MidHG. ê, êwe, f., ‘customary right, justice, law, marriage,’ OHG. êwa, f., ‘law, marriage’; corresponds to OSax. êo, m., ‘law,’ Du. echt, ‘marriage’ (from ê-haft, see echt), AS. œ̂, œ̂w, f., ‘law, marriage.’ These West Teut. cognates aiwi- might be derived from aigwí-, aihwí-, and connected with Lat. aequum (base aiqo-). To this there is no objection from the linguistic standpoint, for it is probable that the cognates similar in sound and signifying ‘time, eternity,’ are totally different from those just quoted; comp. Goth. aiws, OHG. êwa, AS. œ̂, œ̂w, ‘time, eternity,’ which are allied to Lat. aevum, aeternus, Gr. αἰών, αἰεί; so too Sans. aỹas, ‘duration of life.’ Yet the first group might also perhaps be connected with Sans. êva, m., ‘progress, course, procedure, custom.’