سُنَنُ ابْنِ مَاجَهْ
Sunan Ibn Majah 275
The Book of Purification and its Sunnah
The key to prayer is purification
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، عَنْ سُفْيَانَ، عَنْ عَبْدِ اللَّهِ بْنِ مُحَمَّدِ بْنِ عَقِيلٍ، عَنْ مُحَمَّدٍ ابْنِ الْحَنَفِيَّةِ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ مِفْتَاحُ الصَّلاَةِ الطُّهُورُ وَتَحْرِيمُهَا التَّكْبِيرُ وَتَحْلِيلُهَا التَّسْلِيمُ .
It was narrated from Muhammed bin Al-Hanafiyyah that his father said: "The Messenger of Allah said: 'The key to prayer is purification, its opening is to say 'Allahu Akbar' and its closing is to say As-salamu 'alaikum.'"
Sunan Ibn Majah, 275Hasan (Darussalam)