Halakhah su Deuteronomio 23:15

It is prohibited to recite sacred words in the presence of erva (nakedness), as the Torah states: “Your camp must therefore be holy. Let Him not see any erva among you and turn away from you” (Devarim 23:15). Regarding a man who sees another man or a woman who sees another woman, it is only prohibited to recite sacred words in view of the other’s privates. Therefore, if a woman is sitting on the floor or a chair in a manner that conceals her private part, even if she is naked, another woman may pray or speak sacred words in her presence (MB 75:8).

The Kapaḥ edition of Rambam's Commentary on the Mishnah contains an entirely different reading. According to that version, Rambam declares, "They disagree only with regard to a war against nations which wage war against [Israel] in order to weaken [those nations]." The situation described cannot be understood as one involving actual hostilities against Israel because, as stated by Me'iri, a war of defense constitutes a milḥemet mizvah even according to the Sages. Such defensive war is recognized by Rambam himself as constituting a milḥemet mizvah as indicated by his inclusion of war "to deliver Israel from an enemy who has attacked them" in the category of milḥamot mizvah in his codification of this concept in the Mishneh Torah. Hence the situation depicted as a milḥemet reshut undertaken "to diminish the heathens so that they shall not march upon them" must involve circumstances in which the heathens have as yet not engaged in actual hostilities but whose aggressive intentions are announced or are readily apparent.¹⁹Rema’s ruling is, of course, entirely consistent with the position espoused by Arukh ha-Shulḥan he-Atid. However, as noted earlier, the preponderance of rabbinic authority is contra the position of Arukh ha-Shulḥan he-Atid. Thus, for example, Ḥazon Ish, as noted, declares that war “to deliver Israel from an enemy” constitutes a milḥemet miẓvah only when the enemy has actually “come upon them”—terminology directly contradictory to that employed by Rema.
It should be noted that, in a statement dated 9 Tammuz 5742, the Chief Rabbinate Council of the State of Israel declared the war of Shalom ha-Galil to constitute a milḥemet miẓvah. The war is described as necessary “to deliver Israel from an enemy” and Rema, Oraḥ Ḥayyim 330:6, is cited as broadening this category to encompass deliverance from a putative attack. It is, however, difficult to determine whether that proclamation is intended to be understood as halakhic or hortative in nature. The same statement continues with a discussion of the conduct of the Israeli Defense Forces and cites the verse “and your camp shall be holy” (Deuteronomy 23:15) in what can only be described as a homiletic vein. In its halakhic context, Deuteronomy 23:15 constitutes an exhortation to implement certain hygienic measures. This statement was published in its entirety in the Algemeiner Journal, July 16, 1982, p. 5. An English translation appeared in the London Jewish Chronicle, July 23, 1982, p. 35. The circumstances depicted in the Kapaḥ version of the Commentary on the Mishnah are roughly the equivalent of a state of belligerence as distinct from a state of war.

If there is "nakedness" behind a [glass] lamp and one sees it through the [glass] walls [of the lamp], it is forbidden to recite [Sh'ma] in front of it, as is written, "...let Him not find anything unseemly among you" (Deut. 23:15) and here, it is seen.