Uncircumcised lips - An uncircumcised ear is one that does not hear clearly; an uncircumcised heart one slow to receive and understand warnings; uncircumcised lips, such as cannot speak fluently. The recurrence of the hesitation of Moses is natural; great as was the former trial this was far more severe; yet his words always imply fear of failure, not of personal danger (see Exodus 3:11).

Uncircumcised lips? - The word ערל aral, which we translate uncircumcised, seems to signify any thing exuberant or superfluous. Had not Moses been remarkable for his excellent beauty, I should have thought the passage might be rendered protuberant lips; but as this sense cannot be admitted for the above reason, the word must refer to some natural impediment in his speech; and probably means a want of distinct and ready utterance, either occasioned by some defect in the organs of speech, or impaired knowledge of the Egyptian language after an absence of forty years. See Clarke's note on Exodus 4:10.

And Moses spake before the Lord,.... Who appeared in a visible form, and had spoke to him with an articulate voice, and before whom Moses stood, and made the following reply:

saying, behold, the children of Israel have not hearkened unto me; even though he brought a comfortable message to them from the Lord, and delivered many gracious promises of his to them, assuring them of deliverance out of Egypt, and of their possession of the land of Canaan:

how then shall Pharaoh hear me? making a demand upon him to part with a people, from whose labour he receives so much advantage, and has such an addition to his revenues, and who is a mighty king, and haughty monarch. And this is further enforced from his own weakness and unfitness to speak to Pharaoh:

who am of uncircumcised lips? had an impediment in his speech, could not speak freely and readily, but with difficulty; perhaps stammered, and so uttered superfluous syllables, repeated them before he could fully pronounce what he aimed at; or in other words, he was not eloquent, which was his old objection, and had been fully answered before: and by this it appears that there was no alteration in the speech of Moses since God spoke with him at Mount Horeb. Some think Moses expected to have had this impediment removed, and tacitly hints at it here, not being so well satisfied with Aaron's being joined with him as his mouth and spokesman, which seemed to carry in it some reflection upon him.

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 {d} uncircumcised lips?

(d) Or barbarous and rude in speech and by this word

(uncircumcised) is signified the whole corruption of man's nature.

6:12 Behold, the children of Israel have not hearkened to me; they gave no heed to what I have said, how then shall Pharaoh hear me? - If the anguish of their spirit makes them deaf to that which would compose and comfort them, much more will his pride and insolence, make him deaf to that which will but exasperate him. Who am of uncircumcised lips - He was conscious to himself that he had not the gift of utterance.

12. how then shall . who am of uncircumcised lips?-A metaphorical expression among the Hebrews, who, taught to look on the circumcision of any part as denoting perfection, signified its deficiency or unsuitableness by uncircumcision. The words here express how painfully Moses felt his want of utterance or persuasive oratory. He seems to have fallen into the same deep despondency as his brethren, and to be shrinking with nervous timidity from a difficult, if not desperate, cause. If he had succeeded so ill with the people, whose dearest interests were all involved, what better hope could he entertain of his making more impression on the heart of a king elated with pride and strong in the possession of absolute power? How strikingly was the indulgent forbearance of God displayed towards His people amid all their backwardness to hail His announcement of approaching deliverance! No perverse complaints or careless indifference on their part retarded the development of His gracious purposes. On the contrary, here, as generally, the course of His providence is slow in the infliction of judgments, while it moves more quickly, as it were, when misery is to be relieved or benefits conferred.

6:10-13 The faith of Moses was so feeble that he could scarcely be kept to his work. Ready obedience is always according to the strength of our faith. Though our weaknesses ought to humble us, yet they ought not to discourage us from doing our best in any service we have to do for God. When Moses repeats his baffled arguments, he is argued with no longer, but God gives him and Aaron a charge, both to the children of Israel, and to Pharaoh. God's authority is sufficient to answer all objections, and binds all to obey, without murmuring or disputing, Php 2:14.