Reward of safeguarding one’s tongue

From my father (ra) through Saʿd ibn ʿAbdullāh, from Muʿāwiyah ibn Ḥukaim, from Muʿammar ibn Khallād, from Abū al-Ḥasan al-Riḍā (AS), from his father, who said that Abū ʿAbdullāh (AS) stated: "The salvation of a believer lies in safeguarding his tongue." And Amīr al-Muʾminīn (AS) said