Surah Saba, Verse 46
۞ قُلْ إِنَّمَآ أَعِظُكُم بِوَٰحِدَةٍ ۖ أَن تَقُومُوا۟ لِلَّهِ مَثْنَىٰ وَفُرَٰدَىٰ ثُمَّ تَتَفَكَّرُوا۟ ۚ مَا بِصَاحِبِكُم مِّن جِنَّةٍ ۚ إِنْ هُوَ إِلَّا نَذِيرٌۭ لَّكُم بَيْنَ يَدَىْ عَذَابٍۢ شَدِيدٍۢ
Translation — Sahih International
Say, "I only advise you of one [thing] - that you stand for Allah, [seeking truth] in pairs and individually, and then give thought." There is not in your companion any madness. He is only a warner to you before a severe punishment.
Source
Kur'an-ı Kerim, Sebe' Suresi 34:46
https://kuran.diyanet.gov.tr/mushaf/kuran-meal-2/34-suresi-46-ayet