وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ اسْتَقِيمُوا وَلَنْ تُحْصُوا وَاعْمَلُوا وَخَيْرُ أَعْمَالِكُمُ الصَّلاَةُ وَلاَ يُحَافِظُ عَلَى الْوُضُوءِ إِلاَّ مُؤْمِنٌ ‏"‏ ‏.‏

Yahya related to me from Malik that he had heard that theMessenger of Allah, may Allah bless him and grant him peace, said,"Try to go straight, although you will not be able to do so. Act, andthe best of your actions is the prayer. And only a mumin is constantin his wudu." Translation Not Available

Book reference: Muwatta Imam Malik Book 2 Hadith 67
Web reference: Muwatta Imam Malik Book 2 Hadith 37