Seventh month, on the tenth day - The month Ethanim or Tisri, as being the seventh in the Sacred year, has been called the sabbatical month. On the first day was celebrated the Feast of Trumpets Leviticus 23:24, the tenth day was the Day of Atonement, and on the fourteenth day the Feast of tabernacles commenced (Leviticus 23:24 note; Exodus 23:16).
Afflict your souls - The old term for fasting; but its meaning evidently embraces, not only abstinence from food, but that penitence and humiliation which give scope and purpose to the outward act of fasting. The Day of Atonement was the only public fast commanded by the Law of Moses. See further directions in Leviticus 23:27-32. On fasts observed in later times, see Zechariah 8:19, and margin reference.
A stranger that sojourneth among you - Rather, the foreigner who dwelleth among you. See Exodus 20:10 note. The meaning is, one of foreign blood, who dwelt with the Israelites, had abjured false gods, and had become familiarly known to his neighbors, e. g. the Kenites (Judges 4:11, etc.); the Gibeonites Joshua 9; and a considerable portion of the “mixed multitude” (compare Exodus 12:38, Exodus 12:48). As the foreigner had the blessing and protection of the Law he was bound to obey its statutes.