Surah Saba, Verse 46

۞ قُلۡ إِنَّمَآ أَعِظُكُم بِوَٰحِدَةٍۖ أَن تَقُومُواْ لِلَّهِ مَثۡنَىٰ وَفُرَٰدَىٰ ثُمَّ تَتَفَكَّرُواْۚ مَا بِصَاحِبِكُم مِّن جِنَّةٍۚ إِنۡ هُوَ إِلَّا نَذِيرٞ لَّكُم بَيۡنَ يَدَيۡ عَذَابٖ شَدِيدٖ٤٦

qul innamā aʿiẓukum biwāḥidatin an taqūmū lillahi mathnā wafurādā thumma tatafakkarū mā biṣāḥibikum min jinnatin in huwa illā nadhīrun lakum bayna yaday ʿadhābin shadīdin

Say, "I only advise you of one [thing] - that you stand for Allāh, [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.