Surah Az-Zumar — Ayah 65 (39:65)
وَلَقَدۡ أُوحِيَ إِلَيۡكَ وَإِلَى ٱلَّذِينَ مِن قَبۡلِكَ لَئِنۡ أَشۡرَكۡتَ لَيَحۡبَطَنَّ عَمَلُكَ وَلَتَكُونَنَّ مِنَ ٱلۡخَٰسِرِينَ ٦٥
English translation (Saheeh International)
And it was already revealed to you and to those before you that if you should associate [anything] with Allāh, your work would surely become worthless, and you would surely be among the losers.
Brief commentary
Allah had revealed to you, O Messenger, and to the messengers before you: If you worship others together with Allah the reward of your good deeds will be void and you will be of the losers in the world due to the loss of your religion and in the Hereafter due to the punishment.