Surah Al-Qasas, ayah 34

وَأَخِي هَٰرُونُ هُوَ أَفۡصَحُ مِنِّي لِسَانٗا فَأَرۡسِلۡهُ مَعِيَ رِدۡءٗا يُصَدِّقُنِيٓۖ إِنِّيٓ أَخَافُ أَن يُكَذِّبُونِ ٣٤

Wa akhī hārūnu huwa afsahu minnī lisānan fa arsilhu ma'iya rid'an yusaddiqunī innī akhāfu an yukaddhibūn

And my brother Aaron is more fluent than me in tongue, so send him with me as support, verifying me. Indeed, I fear that they will deny me."