An Etymological Dictionary of the German Language/gewähren
gewähren, vb., ‘to be surety for, guarantee, attest,’ from MidHG. gewërn, OHG. giwërên, ‘to grant, confess, perform, pay, give security,’ also the equiv. MidHG. wern OHG. wërên; corresponding to OFris. wera, ‘to give security.’ From the OHG. partic. wërênto, ‘guarantor,’ were adopted the Romance cognates, Ital. guarento and Fr. garant, ‘bondsman’ (allied to Fr. garantir, Ital. guarentire, ‘to give security,’ whence ModHG. Garantie, E. warrant). The connecting link between the OTeut. wk. verbal stem werai-, ‘to confess,’ and non-Teut. words has not yet been found; perhaps Ir. feraim, ‘I give,’ is allied.