rashi on terumah

Rashi comments something very interesting regarding a messenger who you ask to do terumah for you. It says in the gemara that if you do not know how much the person who told you to give terumah (the ba’al habayit) wants you to give (if he forgot to tell you or something along those lines), then you gather according to what you think he would gather. There is one problem. What if you don’t know or have a clue what the ba’al habayit would give? The gemara answers that you should just give in the middle and give 1/50^th. I had an obvious question on this so of course I immediately looked in Rashi who apparently helped me out. My question was: How is 1/50^th in the middle, what is it in the middle of? Rashi answered me by saying that a good/generous man, then he would give 1/40^th, and a bad (or should I say not as generous) man, would give 1/60^th. Now, I understand what the gemara means by 1/50^th being in the middle: it is in the middle of what a generous and not generous man would give.

It is a good idea to all of my fellow classmates to look in Rashi when they have a problem with something because most of the time, he will answer your questions. In this case, he answered mine, however, we did go over it a little, after I looked at the Rashi, in class also.