Narrated by:'Abdullah bin 'Amr said
It was narrated that 'Abdullah bin 'Amr said:"The Messenger of Allah said: 'Adhere to righteousness even though you will not be able to do all acts of virtue. Know that among the best of your deeds is prayer and that no one maintains his ablution except a believer.'"
حَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ بْنِ حَبِيبٍ، حَدَّثَنَا الْمُعْتَمِرُ بْنُ سُلَيْمَانَ، عَنْ لَيْثٍ، عَنْ مُجَاهِدٍ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " اسْتَقِيمُوا وَلَنْ تُحْصُوا وَاعْلَمُوا أَنَّ مِنْ أَفْضَلِ أَعْمَالِكُمُ الصَّلاَةَ وَلاَ يُحَافِظُ عَلَى الْوُضُوءِ إِلاَّ مُؤْمِنٌ " .
IbnMaja
The Book of Purification and its Sunnah • Hadith 278