Muwatta Imam Malik (Riwayat Ibn al-Qasim)

It is narrated from Abu Salamah bin Abdur Rahman (may Allah have mercy on him) that Sayyiduna Abu Hurairah (may Allah be pleased with him) led them in prayer, and recited "When the sky is split asunder" «إِذَا السَّمَاءُ انشَقَّتْ» (Surah Inshiqaq), then during this recitation he performed a prostration, and when he finished the prayer with salam, he informed the people that the Messenger of Allah (peace and blessings be upon him) had performed a prostration in it.