Surah Ah-Shu'ara' (The Poets), Verse 13

وَیَضِیْقُ صَدْرِیْ وَلَا یَنْطَلِقُ لِسَانِیْ فَاَرْسِلْ اِلٰی هٰرُوْنَ ۟

Wa yadeequ sadree wa laa yantaliqu lisaanee fa arsil ilaa Haaroon

“"My breast will be straitened. And my speech may not go (smoothly): so send unto Aaron.”

Quran 26:13 (Yusuf Ali Translation)