http://revach.net/article.php?id=4383

Section: Parshas HaShavua   Category: Quick Vort
Parshas Truma: Bais HaLevi - Truma Comes After Mishpatim
The Bais HaLevi explains that Parshas Truma comes right after Mishpatim for a very important reason.  The Mishkan was built from donations of the Bnei Yisroel.  If a mitzva is done with a stolen item it is pasul because it is a Mitzva Haba B'Aveira, a mitzva performed through an aveira.  Mitzvos like that are not wanted by Hashem.

The halachos of monetary matters are complex.  Rav Yisroel Salanter once warned a Talmid who stopped pursuing a career in the Rabbinate because he did not want to take responsibility for answering halachic questions, that money matters are far more complex than answering questions about treif chickens.

Before one is ready to donate money to build a Makom of Hashra'as HaShechina he needs to make sure that he knows all the halachos pertaining to business and the money is clean and earned with 100% honesty.  If you don't know Mishpatim, your Truma may not be worth anything.