Sura 45 Al-Jathiyah (The Crouching), aya 18

1. ثُمَّ جَعَلْنَاكَ عَلَىٰ شَرِيعَةٍ مِنَ الْأَمْرِ فَاتَّبِعْهَا وَلَا تَتَّبِعْ أَهْوَاءَ الَّذِينَ لَا يَعْلَمُونَ

   Then We put you, (O Muhammad), on an ordained way concerning the matter (of religion); so follow it and do not follow the inclinations of those who do not know.

   45:18

Tafsiri: Saheeh International