The first letters of “Zikhru Torat Moshe (be mindful of Moshe’s Torah)” (Malachi 3:22) spell TaMmuZ without the vav. This is because it is then, in Tammuz, that we must elicit mindfulness in order to rectify forgetfulness. For it was then that forgetfulness came into existence; as a result of the Tablets being broken in the month of Tammuz, forgetfulness came into being. As our Sages, of blessed memory, said: Had the first Tablets not been shattered, the Torah would not have been forgotten by the Jews (Eruvin 54a).

Thus, the vav is missing from Tammuz, as mentioned above. This is because as a result of the Tablets having been broken, the vav departed. For the Tablets are the aspect of vav, as our Sages, of blessed memory, said: The Tablets were vav handbreadths long by vav handbreadths wide (Bava Batra 14a).

The first letters of “Zman Matan Torateinu (the season of the Giving of our Torah)” (Amidah of Shavuot) also spell TaMmuZ. For the Tablets were given in Tammuz, as taught by our Sages, of blessed memory (Yoma 4b). Here, too, the vav is missing, because the Tablets—being the aspect of vav—were broken then.