Sayyiduna Mu'awiyah (may Allah be pleased with him) narrates: I saw the Prophet (peace and blessings be upon him) sucking his tongue (the narrator is unsure; perhaps the words are:) his lip. The narrator says: This refers to Sayyiduna Imam Hasan bin Ali (may Allah be pleased with him). (Sayyiduna Mu'awiyah (may Allah be pleased with him) said:) No lip or tongue that the Prophet (peace and blessings be upon him) has sucked will be punished.
Ahmad recorded it, and apart from the narrator Abd al-Rahman bin Abi Awf, all the narrators of this report are the narrators of the Sahih, and that narrator too is thiqah (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 15047
Hadith Gradingمحدثین:إسنادہ صحیح
Hadith Takhrij«اخرجه الطبراني فى المعجم الصغير (93/4) ، أخرجه مسند أحمد برقم: 16406»