After the incident of the golden calf, Moshe ascended Mount Sinai, pleading with HaShem for forgiveness. Indeed, after some time, Moshe descended with new tablets on Yom Kippur, replacing the ones he had previously shattered.
Following this, Moshe informed Am Yisrael that it was time to build the Tabernacle. He gathered everyone and asked them if they would like to give contributions to building it. He told everyone it was completely voluntary, and they were not obligated to make a donation. The verses describe to us the excitement of the Jewish people to contribute to the Tabernacle. Because of their great enthusiasm, the money dedicated quickly started to pile up. It was so much, that it reached the point where Moshe had to command them to stop. Now they were actually commanded to do the opposite and to stop giving.
When discussing Am Yisrael stopping their contributions, the pasuk uses a very interesting choice of word: “ויכלא העם מהביא,” which comes from the word “כלא,” meaning “prison.” We see from here that Am Yisrael wanted to give so badly that they actually had to be forced and “jailed” to stop. The rabbis in the Talmud Yershalmi said it is very difficult to understand Am Yisrael. Nobody can really determine the characteristics of Am Yisrael. When they were asked to give for the golden calf, they gave generously. When they were asked again to give for the Tabernacle, they again gave generously. But, aren’t these two things polar opposites? How could they have this same excitement for both things, despite being so different. It’s like someone who enthusiastically votes for one party and constantly talks about how it is so much more right the other party is, and then suddenly switches to the other with the same energy and loyalty.
The Nobel Prize winning psychologist, Daniel Kahneman, explains that in our brains, we have two systems: The slow brain, and the fast brain. The fast brain is responsible for making quick, instinctual actions. This system is driven by emotions and only considers short-term consequences. The slow brain, on the other hand, is driven by thinking and logic, and is built off of long-term thinking and planning based of off future consequences. Throughout our lives, we need both of these systems, especially in Jewish life. Many times, we get excited by many things and we let the fast brain control the slow brain. This is why the sages taught us, “סוף מעשה מחשבה תחילה,” thinking comes before acting. When we use the fast brain, we don’t think and are only focused on our emotions. Instead, we have to focus on using our slow brain and think before we make an action.
Perhaps we can say that this explains what the Gemara in Shekalim, page 4b, says that Moshe struggled with four things, one of which is the half-shekel given by Am Yisrael. The Gemara questions how he struggled with this, as it doesn’t really have any complexity to it. The answer there is that he was baffled how something so something small could possibly atone for their great sin of the golden calf. Thus, HaShem showed him the fire there is in this Mitzvah, meaning to say that He showed Moshe how powerful the balance of the fast and slow brains is. The fire represents the excitement Am Yisrael have for mitzvot. Even though the half-shekel was such a small amount, it was done consistently and with excitement.