There is a Possuk in this week’s Parsha that states: אֵלֶּה הַדְּבָרִים אֲשֶּר דִבֶּר מֹשֶּה וְּגּוֹ׳ “These are the words which Moshe spoke etc” and RaShI explains [why these things are said as an allusion] because they are words of rebuke and the Pessukim there enumerate all the places that they [The B’nei Yisroel] angered HaShem in them therefore the words of the Possuk conceal the incidents and only allude to them as an imputation out of respect for the B’nei Yisroel.
RaShI states: Since these are words of rebuke and he [Moshe] enumerates here all the places where they angered the Omnipresent, therefore it makes no explicit mention of the incidents [in which they transgressed], but rather merely alludes to them, [by mentioning the names of the places] out of respect for Yisroel (cf. Sifrei).
On the words “In the desert” RaShI states: ...for their having angered Him in the desert by saying, “If only we had died [by the hand of HaShem]” (Shmos 16:3).
On the words “In the plain” RaShI states: in the plain [He rebuked them] regarding the plain, for they had sinned with [the worship of] Baal-Peor at Shittim in the plains of Moav (Bamidbor. 25:1-9). [from Sifrei].
On the words “Opposite the Red Sea” RaShI states: [He rebuked] them regarding their rebellion at the Red Sea. When they arrived at the Red Sea, they said, “Is it because there are no graves in Egypt [that you have taken us to die in the desert?]” (Shemos. 14:11) Likewise, [they sinned] when they travelled from the midst of the sea, as it is said, “And they were rebellious by the sea, by the Red Sea” (Tehilim. 106:7), as is found in Arachin (15a).
On the words “Between Poron and Tofel and Lovon” RaShI states: Rabbi Yochonon said: We have reviewed the entire Torah, but we have found no place named Tofel or Lovon! However, [the explanation is that] he rebuked them because of the foolish things they had said (תָפְּלוּ) about the manna, which was white (לָבָן), saying “And our soul loathes this light bread” (Bamidbor. 21:5), and because of what they had done in the desert of Poron through the spies. [from Eileh Hadevarim Rabbah, Lieberman].
On the words “And Chazeros” RaShI states: Concerning the insurrection of Korach [which took place in Chazeros] (Eileh Hadevarim Rabbah, Lieberman). Another explanation: He said to them, “You should have learned from what I did to Miriam at Chazeros because of slander; [nevertheless,] you spoke against the Omnipresent” (Sifrei).
On the words “And Di-Zohov” RaShI states: (lit., enough gold). He rebuked them for the calf they had made as a result of their abundance of gold, as it is said: “and I gave her much silver and gold, but they made it for Baal” (Hosea 2:10). (cf. Sifrei; Ber. 32a, Eileh Hadevarim Rabbah, Lieberman)
Therefore, the Possuk conceals the incidents and only alludes to them as an imputation out of respect for the B’nei Yisroel.