Surah Mulk will intercede for him until he is Forgiven
It was narrated from Abu Hurayrah that the Prophet (peace and blessings of Allaah be upon him) said:
“A soorah from the Qur’aan containing thirty verses will intercede for a man so that he will be forgiven. It is the soorah Tabaarak Alathi bi yadihi’l-mulk [i.e., Soorat al-Mulk].”
Narrated by al-Tirmidhi, 2891; Abu Dawood, 1400; Ibn Maajah, 3786. Al-Tirmidhi said, this is a hasan hadeeth. It was classed as saheeh by Shaykh al-Islam Ibn Taymiyah in Majmoo’ al-Fataawa, 22/277, and by Shaykh al-Albaani in Saheeh Ibn Maajah, 3053.