Command Aaron and his sons, saying: this is the law of the burnt offering... (Lev. 6:2)
Aaron was commanded to bring the burnt offerings. Until this point the offerings were introduced with the word "say," or "speak." Now the verse urges the bringing of the burnt offering with the expression "command." Rashi explains that the expression "command" is relevant to mitzvot that involve a monetary loss, such as the burnt offerings in our verse.
This verse was said in regard to the Kohen Gadol, who was not only the greatest in wisdom but also the wealthiest man. The Torah nevertheless found it necessary to use the more forceful term of command to ensure the mitzvot would be performed even when there is a monetary loss.(1)
Sometimes a person may have a friendly relationship with someone, until some money issue arises, and then this "friend" becomes a totally different person. He's no longer friendly; all he wants is his money. When there is money involved even great people can lose themselves and get blinded. The Talmud(2) states that a person's true character can be determined by his dealings in money matters. If a person is generally a pious individual but when it comes to money he acts different, then he's only pious when it's easy for him - which is not so pious!
There was a rabbi who devoted countless hours to helping his yeshiva spiritually and financially. One day he came to the office and told the secretary that the yeshiva owes him 85 cents. She said, "No problem! But if you don't mind me asking; you do so much for the yeshiva; do you really care about the 85 cents?" He replied, "It's not my 85 cents that I'm worried about. Rather, I'm afraid that next time it will be me who owes the yeshiva money and I may get into the habit of saying, "Oh it's not that much," and I may end up having money that is not mine!"
1. R' Yecheskel Levenstein.
2. R. Ila'i said: By three things may a person's character be determined: By his cup (wine), by his purse and by his anger (Eiruvin 65b).