Shalom Josh,

It's great to hear from you again, and thank you for the great question. Me'ilah does not depend on a loss to Hekdesh, but on the benefit received by the individual. As is clear from Hilchos Me'ilah, Me'ilah applies once there is benefit of a Perutah, even if Hekdesh did not lose anything in practice. This is similar to the case of using vessels of Hekdesh, where there may be no physical loss at all, yet Me'ilah applies because of the benefit (although vessels that regularly have physical loss when used, need a loss in value of a Perutah).

With money there is an additional point. Money is not used as a physical object from which one derives benefit from its substance. Its entire function is its value. Money always serves as a standard of value and exchange, not as an item whose body is normally diminished through use. Although a coin could theoretically suffer material loss, that is not the usual or relevant form of "use" with respect to monetary benefit. Accordingly, the benefit of money lies in making its value available to the user. When money of Hekdesh is used as collateral, the benefit is the very fact that its monetary value is being placed at the borrower's disposal, which itself constitutes benefit of at least a Perutah.

If one were to argue that the money is merely "standing" as collateral and not being actively used, there is an important Halachic consideration to add. It is ruled that a creditor acquires a Mashkon and is considered a Shomer Sachar for it, as stated in Bava Metzia 82a and codified by the Rambam in Hilchos Sechirus, as well as in Shulchan Aruch (CM 72). This shows that the money has a different Halachic status while pledged, having partially left the domain of the owner and entered that of the lender. On this basis, Me'ilah would take effect at the moment the collateral is given, when the monetary value of Hekdesh is being used for a mundane purpose.

Even if one were to assume that a creditor does not fully acquire the Mashkon, there would still be room to consider whether the very act of placing the value of the money as collateral constitutes benefit and use, though that point would require further analysis.

In any case, the fact that the loan is later repaid and the money returned intact to Hekdesh does not undo the Me'ilah, which would already have taken effect at the time of the pledge and use.

Kol Tuv,

Aharon Steiner