All About The Giving

Rashi says that the terumas hamishkan had to be given לשמה (לי-לשמי.)  Why does there have to be an emphasis that it should be given with intent for the mitzvah, every mitzvah is supposed to be done with intent of fulfilling the mitzvah?  The Tavas Gomah asks why is there a requirement that the terumah be given לשמה, we find many sources where its clear that one fulfills the mitzvah of tzedakah even without intent?  Each of these questions answers the other one.  One would have thought that the mitzvah is like tzedakah, the mitzvah is to support the mikdash and it could be fulfilled even if the donation wasn’t purely given for the sake of the mitzvah, קמ"ל  that isn’t the case over here, there is a mitzvah of giving.  When it comes to tzedakah, one fulfills the mitzvah because the point is that the poor person should be supported and that is accomplished even if the giver didn’t have intent for the mitzvah.  However, when it comes to donating to the mishkan, the mitzvah is the act of giving. 

Why is the mitzvah specifically to give?  The possuk in Shir Hashirim 3:10 describes the inside of the mishkan as being adorned with love.  The mishkan reflected the closeness of Hashem with Klal Yisroel.  The donations weren’t to build a building, they were supposed to reflect the love Klal Yisroel felt toward Hashem; hence the donations had to be given with the proper intent.