To pray for purification the prophet made this supplication everyday, and btw it is a great supplication if your someone who wants to become qariib with Allah and not baciid, it goes " Ya Muqallib al-qulub, thabit qalbi calaa diniik" meaning " Owner of the hearts, make my heart be uLon your deen" , the prophet also encouraged reading Surah ikhlas everyday, and the mminimum is 3 Times in the morning and 3 Times in the evening. I'll tell you the reason why, this surah has a great maqam (rank), and the very name ikhlas comes from the word akhlastu or akhlasa which means literally to make pure. SO the surah is the surah, that makes you pure, and that's what it does, murattal xajj (xafidullah), when people come to him wwith their diseases in their hearts (spiritual diseases like xasad, desires etc) he would tell them " ikhlas ikhlas" , reading it daily will help eradicated bad things like waswasa, compulsive thoughts from the shayadeen.When u read the surah read with the niya of you wanting your heart to be purified, and even say " ya allah akhlasnii bi wajhikal karim" inshallah he will respond
Ramadan karim



