1. Emanuel Tov, Textual Criticism of the Hebrew Bible (Minneapolis: Fortress, 2001) 126.
In Exodus 6:12 (NRSV), Moses says to God, who wants him to speak to Pharaoh: "The Israelites have not listened to me; how then shall Pharaoh listen to me, poor speaker that I am?" I learned from Tov that the phrase translated as "poor speaker" is "foreskin of lips" in the Hebrew. Moses was saying that he was of uncircumcised lips.
I wondered if Moses was saying Pharaoh wouldn't take him seriously, since Moses was flawed. "Uncircumcised heart" often means a heart that is unreceptive to God or sinful(Jeremiah 9:26; Ezekiel 44:7, 9; Acts 7:51). Could "uncircumcised lips" imply something similar?
I couldn't find rabbinic wrestlings with this issue, but here's what Rashi says about the phrase:
closed lips: Heb. עִרַל שְׂפָתָיִם, Literally, of “closed” lips. Similarly, every expression of (עָרְלָה) I say, denotes a closure: e.g., “their ear is clogged (עִרֵלָה) ” (Jer. 6:10), [meaning] clogged to prevent hearing; “of uncircumcised (עַרְלֵי) hearts” (Jer. 9:25), [meaning] clogged to prevent understanding; “You too drink and become clogged up (וְהֵעָרֵל) ” (Hab. 2:16), [which means] and become clogged up from the intoxication of the cup of the curse; עָרְלַתבָּשָָׂר, the foreskin of the flesh, by which the male membrum is closed up and covered; “and you shall treat its fruit as forbidden (וְעִרַלְךְתֶּם עָרְלָתוֹ) ” (Lev. 19:23), [i. e.,] make for it a closure and a covering of prohibition, which will create a barrier that will prevent you from eating it. “For three years, it shall be closed up [forbidden] (עִרֵלִים) for you” (Lev. 19:23), [i.e.,] closed up, covered, and separated from eating it.
For Rashi, uncircumcised lips means lips that are clogged, indicating that Moses was slow of speech. Similarly, an uncircumcised heart is one that is clogged and thus dense to the voice of God. And the literal foreskin closes over the you-know-what.
2. Gerson Cohen, “The Talmudic Age,” Great Ideas and Ages of the Jewish People, ed. Leo Schwarz (New York: Random House, 1956) 194.
Cohen calls the Jewish prayers of the rabbinic period "supplicatory and emotional," like Hosea rather than Leviticus. I'd characterize evangelical prayers that way---you know, the type you say in a prayer circle, where you squeeze the hand of the person next to you to let him know it's his turn to pray. But I have a hard time characterizing Jewish prayers that way. That seems to be gathering and saying rote prayers in another language. But who knows? Maybe many Jews say those prayers in an emotional way. Even if the prayers are not words coming directly from their hearts, they sincerely mean every single word that they are reciting. In addition, a classmate of mine, a rabbi, wrote about a healing service that her temple had---which included prayers for physical and spiritual healing. That sounds rather charismatic, but it's occurring in a Jewish house of worship!