In the beginning of Parshas Shekalim, G‑d tells Moshe to instruct the Jewishpeople that they each give a half-shekel “to atone for your souls.” G‑d indicated the exact coin by saying,1This is what they shall give....” Our Sages comment: “G‑d took out a model coin of fire from under His Throne of Glory and showed it to Moshe, saying, ‘Such a coin shall they give.’”2

Tosafos3 explains that “Moshe was perplexed, thinking to himself, ‘What can a person possibly give that will serve as atonement for his soul?’ G‑d therefore showed him a ‘coin of fire.’”

How did the revelation of a “coin of fire” assuage Moshe’s doubts about how a half-shekel coin could grant atonement for one’s soul, especially since it was meant to atone for the Golden Calf, the heinous sin of idolatry.

This will be understood with the following parable:4 A person once served as an apprentice to a silver and goldsmith. The artisan taught his apprentice all the necessary details except for one, which he omitted because of its utter simplicity: in order to melt gold and silver and change its shape, a fire must be lit under the metals.

Setting out on his own, the once-apprentice faithfully followed all the particulars he was taught, leaving out but one “minor” detail — lighting a fire under the silver and gold — that his master had failed to convey. To his utter consternation nothing happened — the silver and gold remained as they were, and he was able to fashion nothing at all. The main “ingredient,” fire, was lacking.

G‑d similarly responded to Moshe by showing him a “coin of fire”: Merely offering a half-shekel coin doesn’t bring about atonement. When, however, that coin is offered with the “fire” and spirit that emanates from the soul’s very essence — “Man’s soul is G‑d’s lamp”5 — then even a half-shekel coin can fully atone for so grievous a sin as the Golden Calf.

This will be better understood by introducing yet another question. The commandment regarding the half-shekel is stated thusly: “This is what they shall give ... a half-shekel; a shekel is twenty gerah, a half-shekel is to be given as an offering to G‑d.”

Why the seemingly excess verbiage; couldn’t the Torah have simply stated that one is to give ten gerah? Evidently the Torah desires to indicate that G‑d specifically wanted that a half-shekel be given — that ten gerah is not an amount that stands on its own, but is half of a complete shekel that consists of twenty gerah.

The Torah always demands that one give G‑d of one’s best.6 Why is an exception made here where we are bidden to give but half a shekel, half of a complete thing? This is especially so, since the half-shekel served as atonement for the idolatrous and fragmenting sin of the Golden Calf, a denial of G‑d’s oneness and unity. Shouldn’t the atonement offering be symbolic of oneness and unity — a complete shekel, rather than the fragmentation of a half-shekel?

The true aspect of unity demanded of a Jew is that he realize that he is not at all an entity unto himself — as he exists on his own he is but a shadow of his true self, half a thing. He becomes an authentic and complete entity only through his union with G‑d.

This feeling and degree of spiritual service elicits and reveals the same aspect above: G‑d’s completeness, as it were, is dependent upon the Jewishpeople. G‑d therefore calls the Jewish people by the appellation Tamasi, “My completion”7 — it is they who make Him, as it were, complete.8

For the bond between a Jew and G‑d is not that of two entities linked together, but of one entity; each without the other is but a half 9 — only as they are together are they truly whole.

This, then, is the notion of the half-shekel. As one complete shekel is composed of twenty gerah: one unit of ten gerah corresponds to the person’s ten soul powers, the other unit of ten gerah corresponds to G‑d’s ten Supernal Attributes. As these units combine they comprise one whole entity of a complete “sacred shekel.”

This is alluded to by the concept of a “coin of fire” — the fire of the essence of the soul that clothes itself in the act of giving the half-shekel. For the commandment of the “half-shekel” demonstrates that the Jewishpeople and G‑d are, as it were, entirely one — something that is accomplished through the unity of the soul’s essence with the essence of G‑d.

This also explains how the half-shekel can act as atonement for the sin of the Golden Calf. No sin, not even the sin of idolatry,10 can affect the soul’s essence — the essence of the soul always remains whole and united with G‑d.

When this essence is revealed — through the half-shekel — then even the revealed powers are affected and they too are unified with G‑dliness. Atonement is then successfully achieved.

Based on Likkutei Sichos, Vol. III, pp. 923-928.