Sister (אָחוֹת, achoth'; ἀδελφή), a term often having, in the style of the Hebrews, equal latitude with brother (q.v.). It is used, not only for a sister by natural relation from the same father and mother, but also for a sister by the same father only, or by the same mother only, or a near relation only (Mt 13:56; Mr 6:3). Sarah is called sister to Abraham (Ge 12:13; Ge 20:12), though only his niece according to some, or sister by the father's side according to others. By the Mosaic law (Le 18:18) it is forbidden to wed the sister of a wife, i.e. to marry two sisters; or, according to some interpreters, to marry a second wife, having one already; literally, "Thou shalt not take a wife over her sister to afflict her," as if to forbid polygamy. Sometimes the word sister expresses a resemblance of conditions and of inclinations. Thus the prophets call Jerusalem the sister of Sodom and of Samaria, because that city delighted in the imitation of their idolatry and iniquity (Jer 3:8,10; Eze 16:45). So Christ describes those who keep his commandments as his brothers and his sisters (Mt 12:50).