Allaah, High and Exalted, says:

﴿وَلَا تَقُولُوا۟ لِمَا تَصِفُ أَلۡسِنَتُكُمُ ٱلۡكَذِبَ هَـٰذَا حَلَـٰلࣱ وَهَـٰذَا حَرَامࣱ لِّتَفۡتَرُوا۟ عَلَى ٱللَّهِ ٱلۡكَذِبَۚ إِنَّ ٱلَّذِینَ یَفۡتَرُونَ عَلَى ٱللَّهِ ٱلۡكَذِبَ لَا یُفۡلِحُونَ﴾ النحل ١١٦

“Do not falsely declare with your tongues, ‘This is lawful, and that is unlawful,’ only fabricating lies against Allah. Indeed, those who fabricate lies against Allah will never prosper.” (An-Nahl 6: 116)

In his commentary on the above verse, As-Suyootee said in his Tafseer (Ad-Durr Al-Manthoor):

Abu Hatim reported on the authority of Abu Nadhrah who said: “Ever since I read this verse; I have always been afraid of giving Fatwa.”