How Musa asked for the Support of His Brother and was granted that by Allah
When Allah commanded him to go to Fir`awn, the one who he had run away from and whose vengeance he feared,
قَالَ رَبِّ إِنِّى قَتَلْتُ مِنْهُمْ نَفْساً
( Musa said: My Lord! I have killed a man among them,) meaning, that Coptic,
فَأَخَافُ أَن يَقْتُلُونِ
(and I fear that they will kill me.) i.e., `when they see me.'
وَأَخِى هَـرُونُ هُوَ أَفْصَحُ مِنِّى لِسَاناً
(And my brother Harun -- he is more eloquent in speech than me,) Musa, peace be upon him, had a speech defect, because when he had been given the choice between a date and a pearl, he mistakenly picked up a coal and placed it on his tongue, so he found it difficult to speak clearly. Musa said:
Continue reading the tafsir of ayahs 33–35 A sermon should have high degree of eloquence
هُوَ أَفْصَحُ مِنِّي لِسَانًا (He is more fluent in his tongue - 28:34). This verse points out that a high degree of oratory and eloquence is desirable for sermons and preaching, and there is no harm if one takes training in that.
Tazkirul Quran
Maulana Wahiduddin Khan
When God appoints somebody as His missionary, He provides him with all that is essential for the performance of the task. Similarly, provision was made for Moses according to his special circumstances. By way of authority for his appointment, he was blessed with the ability to perform certain miracles and he was to be aided by his brother. Moses was endowed with an impressive personality so that Pharaoh’s community may not dare to mishandle him. And it was ordained by God that Moses and his companions should finally be supreme.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.