It is narrated from Sayyiduna Qutbah bin Malik (may Allah be pleased with him) that he said: "I heard the Prophet (peace and blessings be upon him) reciting, 'wa al-nakhla basiqat' (and the tall palm trees) [Surah Qaf: 10] with the letter sad."
No narrator other than Hisham bin Yunus (may Allah have mercy on him) mentioned the words "with the sad" in this hadith.
Hadith Referenceالمعجم الأوسط / باب العين / 4800
Hadith Takhrij«أخرجه الطبراني فى «الصغير» برقم: 690»