The Sufficient (Vol 3) · Hadith 77 (#Ḥadīth #3)
Chapter 12 | Expressions to Say When Entering a Lavatory and When Coming Out
3ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ إِبْرَاهِيمَ بْنِ أَبِي مَحْمُودٍ قَالَ سَمِعْتُ الرِّضَا (عَلَيْهِ الْسَّلام) يَقُولُ يُسْتَنْجَى وَيُغْسَلُ مَا ظَهَرَ مِنْهُ عَلَى الشَّرْجِ وَلاَ تُدْخَلُ فِيهِ الأنْمُلَةُ.
3. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Ibrahim ibn abu Mahmud who has said the following: “I heard abu al-Hassan, al-Rida , say, ‘One should get rid of remaining feces and urine by washing what is outside of the buttocks and there is no need to enter one’s fingers inside.’”
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).