Human nature is to get attached to what we invest in. Whether it’s time, energy, money or any kind of effort-the more we invest in something the more we become attached to it. If we build something from scratch; and with hard work can produce positive results from it then we also feel like the owners and “Masters” of the project.
After working the land of Israel for a number of years there is a danger that the Jewish people will start to see themselves as the “Masters” of the land. After all “I” sewed in the right season and calculated the best time to harvest, and “I” invested months of my time and energy to make this crop a success- and the tremendous yield of the crop even attests to my phenomenal job.
To avoid this danger Hashem commanded us that on the 7th year we are to “let go” of “Our” fields, to demonstrate to ourselves and to the world that we are not the Boss, rather Hashem is the Master of the land and we are merely his servants carrying out his will.
As well, refraining from working “My Land” on Shmittah despite a financial and sovereign loss, protects us from the natural but false feeling that we are the “Masters” of the land.
The concept of Smittah is also relevant to us in our every day to day life. When we refrain from doing something because Hashem commanded us, we demonstrate and declare to the world; and most importantly to ourselves that Hashem is the “Master” and we are his servants.