The twenty first sutta of the Majjhimanikāya, taught to Moliya-
The sutta contains the story of the lady of Sāvatthi, called Vedehikā, who had a reputation for gentleness until tested by her servant girl and found wanting. The saw is only one of numerous similes that occur in the discourse. It is quoted in the Mahāhatthipadopama Sutta (M.i.189), and is elsewhere (e.g., DA.i.123) given as an example of a sutta taught on account of someone’s lack of patience.