It was narrated from ‘Ali (رضي الله عنه) that When the Prophet (ﷺ) sent him with Bara`ah (Soorat At-Tawbah), he said:
“O Prophet (ﷺ) of Allah, I am not eloquent or a good speaker.” He said: “I have no choice but to go myself or send you with it.” Ali (رضي الله عنه) said: “If that is the case, I have no choice but to go.” He said: `Go, and Allah will make your tongue steadfast and guide your heart.` Then he placed his hand over his mouth.