Acts 7:22

And Moses was trained up in all the wisdom of the Egyptians: and he was mighty in words, and in deeds.

1 Corinthians 2:1-4

And I, when I came among you, brethren, came not with excellency of language, or of human wisdom, declaring unto you the testimony of God:

2 Corinthians 10:10

for his letters, say they, are weighty and powerful, but his bodily presence is weak, and his speech contemptible.

2 Corinthians 11:6

yet not in knowledge ---but we have been fully manifested among you in all things.

Treasury of Scripture Knowledge

Summary

And Moses said unto the LORD, O my Lord, I am not eloquent, neither heretofore, nor since thou hast spoken unto thy servant: but I am slow of speech, and of a slow tongue.

Bible References

Eloquent

1 Corinthians 2:1
And I, when I came among you, brethren, came not with excellency of language, or of human wisdom, declaring unto you the testimony of God:
2 Corinthians 10:10
for his letters, say they, are weighty and powerful, but his bodily presence is weak, and his speech contemptible.
2 Corinthians 11:6
yet not in knowledge ---but we have been fully manifested among you in all things.