See on Matt. 10:18, 42; cf. 1 Cor. 5:4. According to the Mishnah (Aboth 3. 2, Soncino ed. of the Talmud, p. 27), “But [when] two sit together and there are words of Torah [spoken] between them, the Shechinah abides among them” (see on Gen. 3:24). The statement of Matt. 18:20 is, of course, true in a general sense, though in the context of the chapter (see vs. 16-19) it refers primarily to the church in its official capacity dealing with an offending member.