אסמכתא-טבילת כלים

There is a concept in Halacha called אסמכתא. It is in its own category of Jewish Law. It is technically rabbinic in nature.

This means that when something is categorized as אסמכתא, it would not be listed among the 613 Mitzvot. It is considered among the strongest of rabbinic laws.

An example of אסמכתא from פרשת מטות is the Mitzva of טבילת כלים, dipping dishes made by a non-Jew into a Mikva. As is typical of אסמכתא, it is learned from כלי מדין, the utensils of the Midyanites.

After the victorious battle with Midyan, the spoils of war that were brought back, included many utensils. Elazar, son of Aharon, gave the command to dip these utensil in a Mikva. This is the source for what we continue to do when purchasing dishes and pots and pans, made by a non-Jew.

It is always important to know how to categorize the various Mitzvot. We apply the principle that when in doubt about Torah laws, we take the strict approach. When in doubt about rabbinic laws, we are lenient. טבילת כלים is not listed among the תרי״ג מצוות. It is an אסמכתא.