حَدَّثَنَا عُثْمَانُ بْنُ أَبِي شَيْبَةَ حَدَّثَنَا وَکِيعٌ عَنْ سُفْيَانَ عَنْ ابْنِ عَقِيلٍ عَنْ مُحَمَّدِ ابْنِ الْحَنَفِيَّةِ عَنْ عَلِيٍّ رَضِيَ اللَّهُ عَنْهُ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّی اللَّهُ عَلَيْهِ وَسَلَّمَ مِفْتَاحُ الصَّلَاةِ الطُّهُورُ وَتَحْرِيمُهَا التَّکْبِيرُ وَتَحْلِيلُهَا التَّسْلِيمُ
سنن ابودوٗد · Hadith 618
Narrated Ali ibn Abu Talib: The Prophet ﷺ said: The key of prayer is purification; takbir (saying "Allah is most great") makes (all acts which break prayer) unlawful and taslim (uttering the salutation) makes (all such acts) lawful.
Translated by Dr. Muhammad Muhsin Khan · Reviewed by Islamic University of Madinah · Published March 2020