39:65 · Az-Zumar
وَلَقَدْ أُوحِيَ إِلَيْكَ وَإِلَى الَّذِينَ مِنْ قَبْلِكَ لَئِنْ أَشْرَكْتَ لَيَحْبَطَنَّ عَمَلُكَ وَلَتَكُونَنَّ مِنَ الْخَاسِرِينَ
But it has already been revealed to thee,- as it was to those before thee,- "If thou wert to join (gods with Allah), truly fruitless will be thy work (in life), and thou wilt surely be in the ranks of those who lose (all spiritual good)".