An Etymological Dictionary of the German Language/Quelle

by Friedrich Kluge

Quelle, f., ‘spring, source,’ first occurs in early ModHG. (naturalised by Luther); a late derivative of the ModHG. str. vb. quellen, MidHG. quëllen, OHG. quëllan. From the variant kal (by gradation qel), derived from OIc. kelda, ‘spring’ (whence Finn. kaltio), and Goth. *kaldiggs, which is implied by OSlov. kladęzĭ, ‘spring’; likewise AS. collen, ‘swollen.’ The prehistoric root gel (gol) is related to Sans. jala, ‘water,’ gal, ‘to curl.’ — quellen, ‘to soak, cause to swell,’ is a factitive of OHG. quëllan, ‘to swell.’