וְאַתָּה תְּצַוֶּה אֶת בְּנֵי יִשְׂרָאֵל
“And you command the Children of Israel” (27:20)
The Medrash Aggadah notes that this is the only Parsha that Moshe’s name is not mentioned. This is because, after the Jewish People sinned with the Golden Calf, Hashem called for their destruction, promising to leave only Moshe behind from which He would build a new nation. Rejecting this proposition, Moshe said that he would follow the fate of his people and said that if their sin was too great to forgive “erase me from Your book”. And, as the Baal Haturim explains from the Gemora “A curse of a sage even made on condition comes true” ; therefore, even though Moshe’s arguments gave way for Hashem to forgive the Jewish People, nonetheless Moshe’s statement to be ‘erased from the book’ was fulfilled in this Parsha.
The question is, why Parshas Tetzaveh?
One answer can be brought from Moshe’s reaction to his first encounter with Hashem, at the burning bush. When Hashem told Moshe to redeem the Jewish People, Moshe argued that Hashem should instead send Aharon, his older brother to lead the Jewish People out of Egypt. Hashem’s response was to remove the title of Kohen Gadol from Moshe and give it instead to Aharon. Even though Hashem grew angry with Moshe’s response, Moshe’s motives were commendable, therefore, in continuation of Moshe’s desire to see his brother so greatly honoured, Parshas Tetzaveh is the most appropriate Parsha for Moshe’s name not to appear. Moshe’s intention was to honour his brother ahead of himself, so in order that Aharon should be given full ‘limelight’, Moshe’s name was removed from the very Parsha which deals with the garments of the Kohen Gadol, in order not to upstage Aharon in any way.
 Except for Devarim where Moshe is speaking as well as the parshas before he is born.
 Shemos 32:32
 Makkos 11a
 Zevachim 102a
 The Baal Haturim however, writes that Moshe’s name was not written together with reference to the garments of the Kohen Gadol so that he would not feel upset at having lost the title of Kohen Gadol. Although see the reference to the previous footnote.