﴿ قَالُوا۟ يَٰصَٰلِحُ قَدْ كُنتَ فِينَا مَرْجُوًّۭا قَبْلَ هَٰذَآ ۖ أَتَنْهَىٰنَآ أَن نَّعْبُدَ مَا يَعْبُدُ ءَابَآؤُنَا وَإِنَّنَا لَفِى شَكٍّۢ مِّمَّا تَدْعُونَآ إِلَيْهِ مُرِيبٍۢ ﴾

“They answered: "O Salih! Great hopes did we place in thee ere this! Wouldst thou forbid us to worship what our forefathers were wont to worship? Because [of this], behold, we are in grave doubt, amounting to suspicion, about [the meaning of] thy call to us!"”

Please check ayah 11:63 for complete tafsir.