An Etymological Dictionary of the German Language/Annotated/rühren
rühren, verb, ‘to stir, move (the feelings); touch,’ from Middle High German ruërn, Old High German ruorern, ‘to put in motion, incite, stir up, bestir oneself, mix, touch’; compare Old Saxon hrôrian, ‘to move, stir, Dutch roeren, Anglo-Saxon hrêran (to which Anglo-Saxon hrêremûs, English reremouse, is allied), Old Icelandic hrœ́ra. We have probably to assume Gothic *hrôzjan, to which hrisjan, ‘to shake,’ and Old Icelandic hress, ‘quick,’ are perhaps allied. See Ruhr. The Teutonic root hrôs (Aryan krâs) has no cognate terms in the other groups.