Wednesday, May 7, 2014

No iron on the altar


The Torah disqualifies stones that have been cut with iron from use for the mizbeiach [altar for offerings to Gd]; according to Sefer haChinuch, this is the fortieth mitzvah in the Torah. There is some debate as to whether we may use stones that were cut before their dedication, but certainly we may not use iron tools to shape the stones once they have been dedicated. (See Tosafot Succah 49a and Minchat Chinuch 40:2.)

Sefer haChinuch explains that iron symbolizes the spilling of blood, as well as general destruction; it is inappropriate to build an altar, the locus of atonement and the site at which blessings and peace are generated, with a destructive tool.

It is noteworthy that we do use iron for other mitzvot. For example, the Rambam ruled that the ideal material for a circumcision knife is iron (Mishneh Torah, Hilchot Milah 2:1; see Perishah to Tur Yoreh Deah 264:7 and Chatam Sofer to Shabbat 134b for fascinating related comments).

Have a great day,


  1. Notice that there are three prohibitions in this paragraph about making an altar (Shemos 20:18-22: not accompanying it with an idol, not using metal (because metal is used in war), and not having steps (because that would reveal ankles -- "lo sigaleh ervaskha").

    And so, in the first mitzvah in the Torah after the revelation at Sinai, we have mention of all three aveiros that are yeihareig ve'al ya'avor.