(י) וַיֹּ֨אמֶר מֹשֶׁ֣ה אֶל־ה' בִּ֣י אדושם לֹא֩ אִ֨ישׁ דְּבָרִ֜ים אָנֹ֗כִי גַּ֤ם מִתְּמוֹל֙ גַּ֣ם מִשִּׁלְשֹׁ֔ם גַּ֛ם מֵאָ֥ז דַּבֶּרְךָ אֶל־עַבְדֶּ֑ךָ כִּ֧י כְבַד־פֶּ֛ה וּכְבַ֥ד לָשׁ֖וֹן אָנֹֽכִי׃
(10) But Moses said to the Eternal, “Please, O Lord, I have never been a man of words, either in times past or now that You have spoken to Your servant; I am slow of speech and slow of tongue.”
(י) כבד פה. בִּכְבֵדוּת אֲנִי מְדַבֵּר. וּבִלְשׁוֹן לַעַז בלב"ו:
(10) כבד פה SLOW OF SPEECH (lit. heavy of mouth) — I speak heavily (with difficulty); old French balbus. (English = stammerer).
If I wanted, I could make you speak beautifully, but I do not want that. It will be to My greater glory if I can make someone of no speech and language fulfill my mission and my desire. He shall do a great thing through his own power.
(א) כי כבד פה וערל לשון אנכי - איני בקי בלשון מצרים בחיתוך לשון, כי בקטנותי ברחתי משם ועתה אני בן שמונים.
(1) כי כבד פה וכבד לשון אנכי, I am not fluent in the Egyptian spoken by the upper classes of the aristocracy. The reason is that I fled Egypt before I had completed my education there and in the meantime I am 80 years of age.
Gersonides: Moses so concentrated on divine matters that he was not good at putting words together.
Abarbanel: He had a harelip and could not pronounce p, b, m, and w.
Rabbi Nachman of Breslov: Moses found it difficult to speak because he represents silence, which transcends speech.
(כו) ויגדל הילד - עשרים וארבעה חודש הניקתהו, ואתה אומר ויגדל הילד?! אלא שהיה גדל, שלא כדרך כל הארץ. ותבאהו לבת פרעה וגו' היתה בת פרעה מנשקת ומחבקת ומחבבת אותו, כאלו הוא בנה, ולא היתה מוציאתו מפלטרין של מלך. ולפי שהיה יפה כל מתאוים לראותו, מי שהיה רואהו לא היה מעביר עצמו מעליו. והיה פרעה מנשקו ומחבקו, והוא נוטל כתרו של פרעה ומשימו על ראשו... והיו שם יושבין חרטומי מצרים, ואמרו: מתיראין אנו מזה, שנוטל כתרך ונותנו על ראשו, שלא יהיה זה אותו שאנו אומרים שעתיד ליטול מלכות ממך. מהם אומרים להרגו, מהם אומרים לשרפו. והיה יתרו יושב ביניהן, ואומר להם: הנער הזה אין בו דעת, אלא בחנו אותו והביאו לפניו בקערה זהב וגחלת, אם יושיט ידו לזהב, יש בו דעת והרגו אותו, ואם יושיט ידו לגחלת, אין בו דעת, ואין עליו משפט מות. מיד הביאו לפניו, ושלח ידו לקח הזהב, ובא גבריאל ודחה את ידו, ותפש את הגחלת והכניס ידו עם הגחלת לתוך פיו ונכוה לשונו, וממנו נעשה (שמות ד, י) כבד פה וכבד לשון.
(26) "And the child (Moses) grew" - Twenty four months she nursed him, and you say "and the child grew"?! Rather he grew, not in the way of the [rest] land. “And she brought him to the daughter of Pharaoh…” The daughter of Pharaoh would kiss and hug and adore him (Moses) as if he were her own son, and she would not take him out of the king’s palace. And because [Moses] was so beautiful, everyone yearned to see him. One that would see him would not leave his presence. And it was that Pharaoh would kiss him (Moses) and hug him, and he would remove Pharaoh’s crown and place it on his own head... And some of the observers sitting among them were the magicians of Egypt that said, “We are wary of this, that he is taking your crown and placing it on his head, that he not be the one we say (i.e. prophesy) that will take the kingship from you.” Some said to kill him, and some said to burn him. And Jethro was sitting among them and said to them, “This child has no intent [to take the throne]. Rather, test him by bringing in a bowl [a piece of] gold and a coal. If he outstretches his hand towards the gold, [surely] he has intent [to take the throne], and you should kill him. And if he outstretches his hand towards the coal, he [surely] does not have intent [to take the throne], and he does not deserve the death penalty.” They immediately brought the bowl before him (Moses), and he outstretched his hand to take the gold, and Gabriel came and pushed his (Moses’) hand, and he grabbed the coal. He then brought his hand along with the coal into his mouth and burned his tongue, and from this was made (Exodus 4:10) “slow of speech and slow of tongue.”
(5) I cried, “Woe is me; I am lost! For I am a man of unclean lips And I live among a people Of unclean lips; Yet my own eyes have beheld The Sovereign Ruler of Multitudes” (6) Then one of the seraphs flew over to me with a live coal, which he had taken from the altar with a pair of tongs. (7) He touched it to my lips and declared, “Now that this has touched your lips, Your guilt shall depart And your sin be purged away.” (8) Then I heard the voice of my Lord saying, “Whom shall I send? Who will go for us?” And I said, “Here am I; send me.”
"Heavy of Mouth" and "Heavy of Tongue" on Moses' Speech Difficulty, by Jeffry Tigay, Bulletin of the American Schools of Oriental Research
History has known other creative geniuses and national leaders, from Demosthenes to Felix Mendelsohn and Churchill, who worked their effect on humanity despite speech impediments. The bible viewed Moshe as an agent of God whose success owed nothing to his natural endowments, but only to the persuasion worked by the words and deeds he uttered and performed under divine direction.
"But I am Slow of Speech": What We Can Learn From Moses, Larry Glickman
This week’s Torah portion this week is Va-eira, the portion that Jewish stutterers around the world – a rather exclusive club of which I am a reluctant member – both celebrate and loathe.
...But do we really know that Moses stuttered at all? All the Bible says is “impeded speech” or “slow of tongue.” Commentators have suggested that, rather than being a stutterer – something I wouldn’t wish upon even an ancient Egyptian! – he just didn’t know how to speak the Egyptian language well. Or, maybe he had a lisp, or he accidentally scorched his tongue, or even more simply, he did not fancy himself a strong public speaker.... God tells Moses to speak no fewer than 70 times in the Bible. Regardless of any impediment Moses may have, he is the leader God has chosen, and Moses is the one he wants to deliver God’s message. The times Moses gets into trouble...are in fact the times he does not speak...
Public speaking is tough. In fact, some people might rather suffer from a lifetime of stuttering rather than be required to speak in front of any kind of a group.... The number one fear among people is speaking in public. The number two fear is death, which...means that the average person attending a funeral would rather be in the casket than giving the eulogy.
I think the importance of this Torah portion for us should not be that Moses might have been a stutterer, but rather that he had an important message to share – and even with what he characterized as a handicap, he shared the message. And he got creative. And he got help from Aaron. And he used props and multimedia. He turned staffs into snakes. He made it rain frogs from the sky. He made the rivers flow red with blood. He did not give up. He was relentless. He believed in what he was saying, and he got people to listen.
https://reformjudaism.org/blog/2016/01/07/i-am-slow-speech-what-we-can-learn-moses