أَخْبَرَنَا مُحَمَّدُ بْنُ كَثِيرٍ، عَنْ الْأَوْزَاعِيِّ، عَنْ مَكْحُولٍ، قَالَ: "السُّنَّةُ سُنَّتَانِ: سُنَّةٌ الْأَخْذُ بِهَا فَرِيضَةٌ، وَتَرْكُهَا كُفْرٌ، وَسُنَّةٌ الْأَخْذُ بِهَا فَضِيلَةٌ، وَتَرْكُهَا إِلَى غَيْرِ حَرَجٍ".
It is narrated from Imam Awza'i, may Allah have mercy on him: Mak'hool, may Allah have mercy on him, said: The Sunnah is of two types; one is that holding onto it is obligatory and abandoning it is disbelief, and the other is the Sunnah that acting upon it is virtuous and there is no harm in leaving it.