Exodus 4:10

4:10 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.

Exodus 6:12

6:12 And Moses spake before the LORD, saying, Behold, the children of Israel have not hearkened unto me; how then shall Pharaoh hear me, who [am] of uncircumcised lips?

Exodus 6:30

6:30 And Moses said before the LORD, Behold, I [am] of uncircumcised lips, and how shall Pharaoh hearken unto me?

Jeremiah 1:6

1:6 Then said I, Ah, Lord GOD! behold, I cannot speak: for I [am] a child.

Zechariah 3:1-7

3:1 And he shewed me Joshua the high priest standing before the angel of the LORD, and Satan standing at his right hand to resist him. 3:2 And the LORD said unto Satan, The LORD rebuke thee, O Satan; even the LORD that hath chosen Jerusalem rebuke thee: [is] not this a brand plucked out of the fire? 3:3 Now Joshua was clothed with filthy garments, and stood before the angel. 3:4 And he answered and spake unto those that stood before him, saying, Take away the filthy garments from him. And unto him he said, Behold, I have caused thine iniquity to pass from thee, and I will clothe thee with change of raiment. 3:5 And I said, Let them set a fair mitre upon his head. So they set a fair mitre upon his head, and clothed him with garments. And the angel of the LORD stood by. 3:6 And the angel of the LORD protested unto Joshua, saying, 3:7 Thus saith the LORD of hosts; If thou wilt walk in my ways, and if thou wilt keep my charge, then thou shalt also judge my house, and shalt also keep my courts, and I will give thee places to walk among these that stand by.

Matthew 12:34-37

12:34 O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh. 12:35 A good man out of the good treasure of the heart bringeth forth good things: and an evil man out of the evil treasure bringeth forth evil things. 12:36 But I say unto you, That every idle word that men shall speak, they shall give account thereof in the day of judgment. 12:37 For by thy words thou shalt be justified, and by thy words thou shalt be condemned.

James 3:1-2

3:1 My brethren, be not many masters, knowing that we shall receive the greater condemnation. 3:2 For in many things we offend all. If any man offend not in word, the same [is] a perfect man, [and] able also to bridle the whole body.