It is narrated from Ibn Mas'ud (may Allah be pleased with him) that he did not perform prostration in Surah (Sad) and said: This is merely the mention of a prophet's repentance.
Hadith Referenceمسند الإمام الشافعي / كتاب الصلاة / 339
Hadith Takhrijأخرجه البيهقي: 2/ 319 وفي معرفة السنن والآثار له (1115) ۔ وعبد الرزاق: 5873.