An Etymological Dictionary of the German Language/helfen
helfen, vb., ‘to help, assist, avail, remedy,’ from the equiv. MidHG. hëlfen, OHG. hëlfan; a common Teut. vb. used in the same sense in all the dialects; comp. Goth. hilpan, OIc. hjalpa, AS. hëlpan, E. to help, Du. helpen, OSax. hëlpan. Teut. root help from pre-Teut. kelb-; a root of another Aryan dialect apparently allied in meaning curiously ends in p (kelp); comp. Lith. szèlpti, ‘to help,’ paszalpà, ‘help’ (in Sans. the root çalp does not occur). Sans. kḷp, ‘to accommodate oneself to, suit,’ is even less closely connected.