Hadith 3:11
Thauban reported God’s messenger as saying, “Keep to the straight path, which you will not be able to do, know that your best action is prayer and that only a believer observes ablution carefully." Malik, Ahmad, Ibn Majah and Darimi transmitted it.
عَنْ ثَوْبَانَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «اسْتَقِيمُوا وَلَنْ تُحْصُوا وَاعْلَمُوا أَنَّ خَيْرَ أَعْمَالِكُمُ الصَّلَاةُ وَلَا يُحَافِظُ عَلَى الْوُضُوءِ إِلَّا مُؤْمِنٌ» . رَوَاهُ مَالِكٌ وَأَحْمَدُ وَابْنُ مَاجَهْ وَالدَّارِمِيُّ
Original Reference: Mishkat al-Masabih 292