﴿ وَإِذَا قِيلَ لَهُمُ ٱتَّبِعُوا۟ مَآ أَنزَلَ ٱللَّهُ قَالُوا۟ بَلْ نَتَّبِعُ مَآ أَلْفَيْنَا عَلَيْهِ ءَابَآءَنَآ ۗ أَوَلَوْ كَانَ ءَابَآؤُهُمْ لَا يَعْقِلُونَ شَيْـًۭٔا وَلَا يَهْتَدُونَ ﴾

“But when they are told, "Follow what God has bestowed from on high," some answer, "Nay, we shall follow [only] that which we found our forefathers believing in and doing." Why, even if their forefathers did not use their reason at all, and were devoid of all guidance?”

Please check ayah 2:171 for complete tafsir.