Leaning for Tachanun

Tachanun, extra supplications, are traditionally recited after the Amidah of Shacharis and Minchah. During one section, the custom is to bow down. Not a full bow, but sitting down and leaning your back and head forward. You rest your head on your arm so it is not directly above the ground without an intervening object (your arm needs to be covered by a sleeve or tallis because a bare arm is not considered intervening -- Magen Avraham 131:2).

The Rokei'ach (no. 324) records a custom not to lean during Tachanun if you are not in a room that has a Torah scroll. This is quoted by the Rema as the prevalent Ashkenazic practice (Shulchan Arukh, Orach Chaim 131:2).

Click here to read moreAccording to this custom, one would presumably not lean when praying in a classroom that lacks a Torah scroll. However, the Kitzur Shulchan Arukh (22:4) quotes a view that any holy book is sufficient for these purposes. As long as there is a Chumash or Gemara in the room, you lean for Tachanun. The Kitzur rejects this view but the Mishnah Berurah (131:11) quotes authorities on both sides: The Sheyarei Knesses Ha-Gedolah holds you should lean while the Derekh Ha-Chaim holds you should not.

When I was in yeshiva, we would pray Minchah in the classroom every day. R. Mayer Twersky said that he asked R. Mendel Zaks (or perhaps his son R. Gershon) whether we should lean. R. Zaks, the son-in-law (or grandson) of the author of Mishnah Berurah, said that we should lean. R. Moshe Feinstein (Iggeros Moshe, Orach Chaim 5:20:5) rules similarly.