وَلَا تَقُولُوا۟ لِمَا تَصِفُ أَلْسِنَتُكُمُ ٱلْكَذِبَ هَٰذَا حَلَٰلٌ وَهَٰذَا حَرَامٌ لِّتَفْتَرُوا۟ عَلَى ٱللَّهِ ٱلْكَذِبَ ۚ إِنَّ ٱلَّذِينَ يَفْتَرُونَ عَلَى ٱللَّهِ ٱلْكَذِبَ لَا يُفْلِحُونَ
6:145.
Commentary:
The opening sentence of the verse may have two interpretations: (a) "and say not on the basis of the falsehood which your tongues utter that this is lawful and this is unlawful"; (b) "and say not about the things which your tongues have falsely declared as lawful or unlawful that this is lawful and this is unlawful". The words "your tongues" mean, "the tongues of the chiefs of people", because it is the leaders who first utter lies; the common people only follow and imitate them.
The verse means to say that it is the exclusive prerogative of God to declare things lawful or unlawful and that if disbelievers do not desist from declaring things lawful or unlawful at will, they will end by forging lies against God. The words, those who forge a lie against Allah do not prosper, embody an infallible criterion by which the truth of a Prophet of God can be tested. A false claimant is a forger of lies against God and such a one can never succeed in his mission.
6:145.