Pidyon Haben
The mitzvah of pidyon haben, mentioned at the end of our parsha (Bamidbar 18:15), is the subject of a scintillating Chassidic exposition in the teachings of Rav Nachman of Breslav, as explicated by his disciple Rav Natan Sternhartz in Likutei Halakhot. Rav Nachman's approach uncovers a hidden meaning in the momentous events of the Exodus, and gives us a new insight into the role of the Jewish people.
Chassidic thought discerns an active aspect in creation, associated with the transmission of a seed or potential for growth and development, and a passive aspect which enables the realization of this potential by accepting and nurturing it. G-d's presence is manifest in the world when these two capacities are properly matched and lead to the propagation - that is the conception, birth and development - of holiness in the world. But without HaShem's active influence, there is no growth; the material world in itself is essentially sterile.
The first-born, as the inauguration and initiation of this process of propagation, naturally symbolizes the essence of the process.
But the sad truth is that the creation does not always acknowledge its sacred Progenitor. The essentially sterile material world, which owes all its growth and development to the spiritual influx from HaShem, sometimes declares independence and arrogantly claims mastery over creation. Its favored target is the "first-born", which symbolizes the power of propagation which is in fact completely lacking from this world, as this power is totally dependent on HaShem.
One of the most audacious attempts at this fraud was the sale of Yosef, who was the first-born of Rachel, Yaakov's primary wife. Yosef was also a tzaddik, one who staunchly maintains his connection with the higher world of holiness; his dreams indicated the proper order of creation, where all creatures would bow down and acknowledge the supremacy of righteousness. (Bereshit 37:7, 37:9.)
Yosef was sold for twenty silver pieces into slavery in Egypt (Bereshit 37:28), the ancient world's outstanding example of thralldom to the flesh, where he faced the most strenuous temptations which sought to sever his connection to holiness and modesty. Eventually, as the first-born, he was the vanguard of the entire family of Israel, all of whom entered the exile of Egypt and faced the resolute efforts of sterile materiality to enslave and extinguish the flowering of holiness.
In the end, our Jewish commitment to righteousness and chastity succeeded in completely overcoming this danger. Egypt did not overcome Israel, who are HaShem's first-born (Shemot 4:22); rather, Egypt's first-born were wiped out. And rather than falling into the hands of the wealth of Egypt, the wealth of Egypt fell into our hands! (Shemot 12:36.) We emptied Egypt of its riches - symbolizing our ability to subordinate our material desires and exploit the treasures of this world in the service of holiness. We took the remains of Yosef with us, symbolizing the utter failure of the carnality of Egypt to ensnare us in the slightest degree. (Shemot 13:19.)
However, the Exodus was only a battle in our continuing and unrelenting war against subordination to material desires, a war which will end only in the time of the final redemption. We have to constantly demonstrate that our "first-born", our power of growth and renewal, comes solely from HaShem. The redemption from the Kohen suggests that the first-born in effect "belongs" to the Kohen, who represents devotion to G-d's service. [It seems that this is particularly important since the sin of the golden calf, where some of the first-born showed that they were still liable to succumb to the rule of gold, of riches. But the tribe of Levi completely resisted this temptation.]
We redeem our first-born from the Kohen for five selaim which are twenty gerah, recalling the twenty silver pieces for which Yosef was sold. (Bamidbar 18:16.) The money which we received from the merchants, who epitomize subordination to earthly concerns, is now given to the Kohen, who epitomize the subordination of earthly concerns to holiness.
We can discern a similar message in the mitzvot pertaining to the first-born of the chamor (donkey), which represents chomer, materiality. We have the ability to redeem the material world by giving its exchange to the Kohen, symbolizing its subordination to holiness; if we are unable to redeem it in this way then we have no choice but to destroy it. (Shemot 13:13.)
(Based on Likutei Halakhot on pidyon bekhor and pidyon peter chamor; see also Igrot Rayah 555.)