Quran 26:194 from Surah Ash-Shu'araa on Divine Marvels.
عَلَىٰ قَلۡبِكَ لِتَكُونَ مِنَ ٱلۡمُنذِرِينَ
English translation: Upon your heart that you may be of the warners
Transliteration: ala qalbika litakuna mina al-mundhirina