People pour their days and energy into gathering material wealth, only to stand helpless before the fleeting nature of life and property. It is a profound tragedy that intense human effort ultimately leaves no lasting mark in the hands of the one who works so hard. Building upon the earlier thought that wealth is often kept to the detriment of its owner, a severe misfortune occurs when this hard-earned wealth simply does not remain with the person [מצודת דוד].
Commentators explore exactly what it is that arrives and departs in such an equal, parallel manner. One approach suggests this cycle refers directly to the money itself. Just as wealth is gathered through great struggle, it can slip away and be lost through difficult circumstances and equal strain [מצודת דוד, רש״י]. Even if a person manages to hold onto their fortune throughout their days, the tragedy peaks at the moment of death, when all riches are left behind and the person holds absolutely nothing [תעלומות חכמה].
Conversely, another perspective views this cycle as a description of human life itself. This is a universal reality for everyone, as people enter the world with nothing and leave the world with nothing [אבן עזרא, ביאור שטיינזלץ]. On a physical level, a person is born delicate and weak, requiring soft food, and eventually returns to that exact same fragile state in old age. Recognizing this inevitable decline is meant to teach humility, reminding people that their physical strength fades away even while they are still alive [תורה תמימה].
In light of this impermanence, a question arises regarding the purpose of working so hard for something as ungraspable as the wind. The primary approach among commentators is that this illustrates an empty, worthless effort that brings no actual benefit. However, another interpretation gives the concept of wind a highly practical meaning. A person can plow, plant, harvest, and thresh their crops, but in the end, separating the edible grain from the useless chaff relies entirely on the wind that God sends into the world. Therefore, people toil with the clear knowledge that the final outcome of their labor depends completely on forces beyond their control [תורה תמימה].