Does Satan Incite Those Who Argue? 1. Does Satan attack places where there is controversy and a lack of peace? For example, a husband and wife who argue constantly. 2. Is this also true for people dealing with mental illness?

Shalom, 1. Indeed, we learned in the Gemara that Satan incites those who engage in dispute, and the place of controversy is Satan's home, whereas a place where peace reigns is not a dwelling for Satan (Gittin 52a; Shmirat HaLashon, Sha'ar HaZechira 15; Dvar Yaakov ad loc. in the name of HaGaon Rabbi Chaim Shmuelevitz). 2. This is a slightly different matter. Satan, as mentioned, incites those who engage in dispute. However, we learned in the Gemara (Berachot 54b) that a sick person requires guarding (shimmur) from harmful spiritual forces (mazikin). Rashi explains that he requires guarding because his fortune (mazal) has been impaired, and therefore the demon (shed) incites against him. See there in the Gemara for other types of people who require guarding besides a sick person. It stands to reason that someone dealing with mental illness is considered "sick" regarding the need for guarding, depending on the severity of the illness. Elaborated Explanation: 1. It is related in the Gemara (Gittin 52a) that there were two people whom Satan incited to sin: every Friday at twilight, they would quarrel with each other. Rabbi Meir happened upon that place and prevented them from quarreling at twilight on Friday for three consecutive weeks until they made peace with one another. Rabbi Meir then heard Satan saying, "Woe (an expression of grief) that Rabbi Meir has expelled that man from his home." When Satan said "that man," he was referring to himself. Thus, he called a place of strife and contention Satan's "home." Similarly, the Chafetz Chaim (Shmirat HaLashon, Part 1, Sha'ar HaZechira, Chapter 15) deduced from this Gemara that Satan incites those who engage in dispute. Furthermore, Satan specifically tries to stir up controversy right before the Sabbath, as the Sabbath is a day of peace and rest (HaGaon Rabbi Chaim Shmuelevitz ad loc., and the notes of HaGaon Rabbi Yosef Shalom Elyashiv ad loc.). One can say that this is why on Friday night we specifically say "Shalom Aleichem, angels of peace"—because the angels help expel the strife that arises on Friday afternoon (Divrei Yatziv, Orach Chaim, Siman 123). 2. The Mishnah Berurah ruled (239:7): "These require guarding from harmful forces: a sick person, a woman who has given birth, a groom, a bride, a mourner. And a Torah scholar at night—meaning when he stands alone in the dark of night." The meaning of "requiring guarding" is that they should not be alone, whether by day or by night, even inside their own home (Aruch HaShulchan, Even HaEzer 64:3). However, since demons are not commonly found nowadays—and see the Shulchan Aruch (Even HaEzer, Siman 17, Se'if 10) that according to the Rambam and the teachers of the Ritva in Yevamot, we do not fear demons today—therefore, for the purpose of a mitzvah, a husband is permitted to leave his sick wife who underwent surgery in order to go to the synagogue. Regarding this, it is said: "He who keeps a commandment will know no evil thing" (Chashukei Chemed, Berachot ad loc.).