Say: "(But) the things that my Lord has indeed forbidden are the Fawahish (immoral deeds) whether committed openly or secretly, and Ithm, and transgression without right, and joining partners with Allah for which He has given no authority, and saying things about Allah of which you have no knowledge. (33)
Fāḥishah', Sin, Transgression, Shirk and Lying about Allah are prohibited
Imam Ahmad recorded that 'Abdullah said that the Messenger of Allah ﷺ said,
لَا أَحَدَ أَغْيَرُ مِنَ اللهِ فَلِذَلِكَ حَرَّمَ الْفَوَاحِشَ مَا ظَهَرَ مِنْهَا وَمَا بَطَنَ، وَلَا أَحَدَ أَحَبُّ إِلَيْهِ الْمَدْحُ مِنَ اللهِ
(None is more jealous than Allah, and this is why He prohibited Fawahish, committed openly or in secret. And none likes praise more than Allah).
This was also recorded in the Two Sahihs. In the explanation of Surat Al-An'am, we explained the 'Fāḥishah' that is committed openly and in secret. Allah said next,
وَالْإِثْمَ وَالْبَغْيَ بِغَيْرِ الْحَقِّ
(and 'Ithm', and transgression without right,)[7:33].
As-Suddi commented, "Al-Ithm means, 'disobedience'. As for unrighteous oppression, it occurs when you transgress against people without justification." Mujahid said, "Ithm includes all types of disobedience. Allah said that the oppressor commits oppression against himself." Therefore, the meaning of, Ithm is the sin that one commits against himself, while 'oppression' pertains to transgression against other people, and Allah prohibited both. Allah's statement,
وَأَن تُشْرِكُوا بِاللَّهِ مَا لَمْ يُنَزِّلْ بِهِ سُلْطَانًا
(and joining partners with Allah for which He has given no authority,) prohibits calling partners with Allah in worship.
وَأَن تَقُولُوا عَلَى اللَّهِ مَا لَا تَعْلَمُونَ
(and saying things about Allah of which you have no knowledge.) such as lies and inventions, like claiming that Allah has a son, and other evil creeds that you – O idolators – have no knowledge of. This is similar to His saying:
فَاجْتَنِبُوا الرِّجْسَ مِنَ الْأَوْثَانِ
(So shun the abomination (worshipping) of the idols)[22:30].