The singular word ‘sunna’ (law, way)2, in all its 14 occurrences in the Quran, also appears always in a negative setting, usually in reference to God’s law or sunnat Allah, which is manifested as the divine law of requital when it involves human actions (8:38, 15:13, 17:77, 18:55, 33:38, 33:62, 35:43, 40:85, 48:23; cf. 3:137, 4:26, 6:34, 6:115, 10:64, 18:27). Exemplified by sunnat al-awalyn (the law/enactment of previous generations, 8:38, 15:13)3, it inflicted penalty on the transgressing ancients as a consequence of their rejection of the messages to follow God’s law.
It is but the same strictly immutable natural law of cause-and-effect that governs the whole Universe and life without being interrupted by any interference (cf. 2:7, 13:11). This consistent Quranic use of the word sunna, solely in conjunction with God, confirms God’s sunna as the only valid sunna and hence obliquely denounces belief in any other ‘sunna’ as shirk. And this explains why the Quran never uses ‘sunna’ in connection with Muhammad or any other messenger.
Rather the followers of man-made sunna, including “Muhammad’s sunna”, receives a stern warning in this verse, which uses the exact word ‘sunna’ to depict, elliptically, the moral penalty they deserved: Are they now but looking for the sunna inflicted on the ancients? For no change will you ever find in God’s sunna, nor will you find any deviation in God’s sunna. 35:43. The message is simple: if you play with fire, you will get burned, through natural law, in the same way as your predecessors!