While Leslau (LS 201) is likely correct to relate it to ṭef ‘to give’, his proposed derivation from PS *ṭwb ‘to be good’ is to be rejected here as well in favor of Arb. wḏ̣f, note especially the X stem with the meaning ‘to take something in its entirety’, from which ‘to enjoy, to profit, to feel satisfied’ could have easily derived.