It was narrated from Abu Hurayrah that the Prophet ﷺ said: “A surah from the Quran 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.
On this basis there is the hope that whoever believes in this surah and reads it regularly, seeking the pleasure of Allah, learning the lessons contained in it and acting in accordance with the rulings contained therein, it will intercede for him [in the Hereafter].
And Allah knows best.