An Etymological Dictionary of the German Language/Reihe
Reihe, f., from the equiv. MidHG. rîke, f., ‘row, line,’ allied to MidHG. rîhen, OHG. rîhan, ‘to range, put on a thread, fix,’ to which MidHG. rige, f., ‘row, line,’ OHG. rī̆ga, ‘line, circular line,’ and Du. rij, ‘row,’ are akin. AS. râw, ‘row, line’ (Goth. *raiwa, for *raigwa, allied to *reihwan), whence E. row is also probably connected with these. The Teut. root rī̆hw, raihw, is related to Sans. rêkkâ, ‘streak, line’ (Aryan root rikh).