“Vayelech Reuven Bimay Kitzir Chitim Vayimtza Dudaim,” “And Reuven went out in the days of the wheat harvest and he found wildflowers.”
Rashi quotes a Gemara in Sanhedrin 99b, which asks why Reuven did not take wheat if it was the wheat harvest? The Gemara answers that Reuven picked wildflowers and not wheat so that he would not run into any problem of theft. He picked something that was Hefker, ownerless, rather than wheat, which could have belonged to an owner. The Torah praises Reuven by telling us that even though it was the wheat-harvesting season, Reuven did not pick wheat out of fear that it was someone else’s. The Gemara deduces that Tzaddikim are people who do not steal. Why was this conclusion necessary? Obviously, if people steal they are not righteous!
Rav Moshe Feinstein zt”l says that the Gemara is teaching us a very important lesson about how careful one should be in order to avoid stealing. One might think that a Tzaddik would never even have the slightest thought to steal, because he knows how wrong it is, however, in reality, if theft is never on his mind, he is more likely to steal something inadvertently. Therefore the Torah tells us that a righteous man never takes his mind off theft out of fear that he might commit this sin by accident. This is why the Torah praises Reuven for taking only wildflowers.
We see that the Torah is teaching a very important lesson, not only in regard to theft, but in regard to all sins: that we should aspire to reach such a high level of righteousness, that we are extremely careful with our actions. And if we should always be aware not to sin, how much more so we should be aware of Mitzvot and rush to do them.