When God sent quail to the Israelites in the wilderness, the Torah says "it covered the camp" (Exodus 16:13). The Mekhilta DeRabbi Yishmael asked the obvious question: covered it to what extent? How deep was this blanket of birds?
The answer comes from a parallel verse in (Numbers 11:31), which describes the quail as piling up "about two cubits deep on the ground." A cubit is roughly eighteen inches, so two cubits means the quail lay about three feet high across the entire camp. But the Mekhilta clarifies that the quail were not heaped in a difficult pile that Israel had to dig through. They were stacked at a height designed for easy gathering.
The rabbis calculated the proportions of the human body to explain why two cubits was the perfect height. From a person's heart downward to the ground is approximately two cubits. From the heart upward to the top of the head is approximately one cubit. This means the quail reached exactly to chest height on a standing person. An Israelite could walk out of his tent, stand upright, and simply take the quail from the top layer without bending down or reaching up.
This seemingly mundane physical detail carries a theological message. God did not merely dump food on the Israelites and leave them to sort it out. He calibrated the delivery to the dimensions of the human body. The quail arrived at exactly the height that required the least effort to collect. Even when giving reluctantly, with a "darkened countenance" as the Mekhilta taught elsewhere, God still made the gathering effortless.