Midrash Rabbah Genesis Volume I, Maurice Simon (39.4M PDF page 346 of 560) Simon's footnote on the "dwarfs"[sic] says: "Kaftor [[[عبرانی زبان|عبرانی]]: כפתור] in Hebrew is a button, and he probably interprets 'Caphtorim' as meaning button-like — little and rotund people."
