Question: If, the “wrong” Sefer Torah was accidentally removed from the Aron Kodesh, may it be returned and exchanged for the “right” Sefer Torah?
Discussion: Most Poskim say that it is improper to return a Sefer Torah to the Aron Kodesh once it has been removed.275 Although using the “wrong” Sefer Torah will cause an inconvenience (tircha detzibbura) since it will take time to roll it to the correct place, it is still considered degrading to a Sefer Torah to be put back once it was taken out. There are two notable exceptions to this rule:
If the Sefer Torah was lifted up but not actually taken out of the Aron Kodesh, it is permitted to set it back down and remove the correct Sefer Torah from the Aron Kodesh.276
On a day on which two (or three) Sifrei Torah are taken out of the Aron Kodesh, and the “wrong” one was laid on the bimah by mistake, it is permitted to pick up the “wrong” Sefer Torah from the bimah and replace it with the “right” one.277
275 See Yabia Omer VIII:15-4, who quotes the various views who rule stringently. See, however, Igros Moshe, Orach Chaim II:37, who rules that one should not object if a member of the congregation instructs the chazzan to return the “wrong” Torah to the Aron Kodesh.
276 Eishel Avraham (Buczacz) 144.
277 Pri Megadim, Mishbetzos Zahav 140:4; Beiur Halachah 684:3, ד"ה ואם טעה. Even if the “wrong” Sefer Torah was already unrolled to the Torah reading of the day (and even if the one called up for the aliyah had already recited “Baruch Atah” but did not yet say Hashem’s Name), it is permitted to roll it up and exchange it for the correct one.