Quran 4:80 from Surah An-Nisaa on Divine Marvels.
مَّن يُطِعِ ٱلرَّسُولَ فَقَدۡ أَطَاعَ ٱللَّهَۖ وَمَن تَوَلَّىٰ فَمَآ أَرۡسَلۡنَٰكَ عَلَيۡهِمۡ حَفِيظٗا
English translation: (He) who obeys the Messenger then surely he obeyed Allah and whoever turns away then not We (have) sent you over them (as) a guardian
Transliteration: man yuti'i al-rasula faqad ata'a al-laha waman tawalla fama arsalnaka alayhim hafizan