Surah An-Nisa, ayah 48

4:48

إِنَّ ٱللَّهَ لَا يَغۡفِرُ أَن يُشۡرَكَ بِهِۦ وَيَغۡفِرُ مَا دُونَ ذَٰلِكَ لِمَن يَشَآءُۚ وَمَن يُشۡرِكۡ بِٱللَّهِ فَقَدِ ٱفۡتَرَىٰٓ إِثۡمًا عَظِيمًا ٤٨

Innallāha lā yaghfiru an yushraka bihī wayaghfiru mā dūna dhālika liman yashā'u waman yushrik billāhi faqadiftarā ithman 'azīmā

Indeed, Allāh does not forgive association with Him, but He forgives what is less than that for whom He wills. And he who associates others with Allāh has certainly fabricated a tremendous sin.