In Devarim 32:48 the pasuk says:
וַיְדַבֵּ֤ר יְהוָה֙ אֶל־מֹשֶׁ֔ה בְּעֶ֛צֶם הַיּ֥וֹם הַזֶּ֖ה לֵאמֹֽר
That very day the LORD spoke to Moses
Rashi on Devarim 32:48 writes:
וידבר ה' אל משה בעצם היום הזה
... בִּשְׁלוֹשָׁה מְקוֹמוֹת נֶאֱמַר בְּעֶצֶם הַיּוֹם הַזֶּה, נֶאֱמַר בְּנֹחַ "בְּעֶצֶם הַיּוֹם הַזֶּה בָּא נֹחַ וְגוֹ'" (בראשית ז')
...בְּמִצְרַיִם נֶאֱמַר "בְּעֶצֶם הַיּוֹם הַזֶּה הוֹצִיא ה'" (שמות י"ב)
And the Lord Spoke to Moses That Very Day
In three places in Scripture the expression בעצם היום הזה is used. It states in the narrative of Noah (Genesis 7:121) That very day entered Noah … [into the ark]”...
Of Egypt, too, it states, (Exodus All. 11) “The very day the Lord did bring [the children of Israel out of the land of Egypt]”...
However, there is another place in Genesis 17:23:
וַיִּקַּח אַבְרָהָם אֶת־יִשְׁמָעֵאל בְּנוֹ וְאֵת כָּל־יְלִידֵי בֵיתוֹ וְאֵת כָּל־מִקְנַת כַּסְפּוֹ כָּל־זָכָר בְּאַנְשֵׁי בֵּית אַבְרָהָם וַיָּמָל אֶת־בְּשַׂר עָרְלָתָם בְּעֶצֶם הַיּוֹם הַזֶּה כַּאֲשֶׁר דִּבֶּר אִתּוֹ אֱלֹהִים
Then Abraham took his son Ishmael, and all his homeborn slaves and all those he had bought, every male in Abraham’s household, and he circumcised the flesh of their foreskins on that very day, as God had spoken to him.
So we see that there are four places in which the term בְּעֶצֶם הַיּוֹם הַזֶּה is used2.
Why doesn't Rashi mention this place in his list?
- Note: The words themselves appear on the next pasuk (Genesis 7:13), It seems Rashi means the beginning of the storyline.
- In fact, Rashi there even gives the same basic explanation of why those words are used (To show that even if others wanted to stop him, they wouldn't have been able to).