Quran 39:65 Az-Zumar, ayah 65 of 75

وَلَقَدْ أُوحِىَ إِلَيْكَ وَإِلَى ٱلَّذِينَ مِن قَبْلِكَ لَئِنْ أَشْرَكْتَ لَيَحْبَطَنَّ عَمَلُكَ وَلَتَكُونَنَّ مِنَ ٱلْخَـٰسِرِينَ ۝٦٥

39:65 And verily it hath been revealed unto thee as unto those before thee (saying): If thou ascribe a partner to Allah thy work will fail and thou indeed wilt be among the losers.