Q. Dear Rabbi. I recently heard that when wearing Tefilin one should not rise his hands overt them, like to pick up a Sefer from a high bookshelf, as this is similar to the Cohen Gadol not rising his hand over the ‘Tzitz’ (golden plate on his forehead with the name of Hashem on it). Is that really true? I have seen even Gedoim do otherwise!

A. Talmud (Sotah 38a) mentions that the Cohen Gadol would not rise his hands over the “Tzitz” or forehead golden plate that had inscribed on it the name of Hashem. Sefer Yereim (269) indeed wonders, since it is understood that the regular Cohanim would wear Tefilin during the Avoda, so why is the lifting of the hand restricted only to the Cohen Gadol? After all the Talmud (Shabbos 12a) mentions that one has to be careful not to forget of the Tefilin one is wearing, as they are more important than the Tzitz, since they have the name of Hashem written many more times in them.

According to the Magen Devorim (128: 8) it would depend on the different opinions if Cohanim actually wore Tefilin at the time of performing the Avoda.
Kovetz Teshuvos (quoted) rules that indeed one wearing Tefilin should not lift his hand over his head to reach for a Sefer or similar.

Horav Shlomo Miller’s Shlit’a opinion is that our common Minhag is not to be concerned.

Rabbi A. Bartfeld as revised by Horav
Shlomo Miller, Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit’a