Easton's Bible Dictionary (1897)
Conjugal infidelity. An adulterer was a man who had illicit intercourse with a married or a betrothed woman, and such a woman was an adulteress. Intercourse between a married man and an unmarried woman was fornication. Adultery was regarded as a great social wrong, as well as a great sin. ” There is, however, no recorded instance of the application of this law. In subsequent times the Rabbis made various regulations with the view of discovering the guilty party, and of bringing about a divorce.
It has been inferred from John 8:1-11 that this sin became very common during the age preceding the destruction of Jerusalem. Idolatry, covetousness, and apostasy are spoken of as adultery spiritually (Jer. 3:6, 8, 9; Ezek. 16:32; Hos. 1:2:3; Rev. 2:22). An apostate church is an adulteress (Isa. 1:21; Ezek. 23:4, 7, 37), and the Jews are styled “an adulterous generation” (Matt. 12:39). (Comp.
Smith's Bible Dictionary (1863)
(Exodus 20:14) The parties to this crime, according to Jewish law, were a married woman and a man who was not her husband. The Mosaic penalty was that both the guilty parties should be stoned, and it applied as well to the betrothed as to the married woman, provided she were free. (22:22-24) A bondwoman so offending was to be scourged, and the man was to make a trespass offering.
(Leviticus 19:20-22) At a later time, and when owing, to Gentile example, the marriage tie became a looser bond of union, public feeling in regard to adultery changed, and the penalty of death was seldom or never inflicted. The famous trial by the waters of jealousy, (Numbers 5:11-29) was probably an ancient custom, which Moses found deeply seated—(But this ordeal was wholly in favor of the innocent, and exactly opposite to most ordeals.
For the water which the accused drank was perfectly harmless, and only by a miracle could it produce a bad effect; while in most ordeals the accused must suffer what naturally produces death, and be proved innocent only by a miracle.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
ADUL'TERY, the crime forbidden in the seventh commandment. According to Jewish law, it is the unlawful intercourse of a man, whether married or not, with a married or betrothed woman not his wife. Gen 38:24, or at least capitally. Under the Mosaic law in the case of the free woman both offenders were stoned. But a bondwoman thus guilty was to be scourged, and the man must make a trespass-offering. Lev 19:20,Lev 19:22.
The so called "water of jealousy," by which the guilt of the accused woman was proven or refuted, was simply some " holy water," or that from the laver which stood near the altar in an earthen vessel, into which dust from the floor of the tabernacle was sprinkled. This mixture was given to the woman, who was solemnly charged by the priest with an oath of cursing. If she was guilty, then by divine interposition — for it contained nothing injurious — this test proved her guilt. If innocent no effect was produced. The accuser in these cases was the husband. Num 5:11-31.
There is no case of the use of this test in Scripture. Adultery is the only ground of divorce recognized by our Lord. Matt 5:32. Adultery is used in the Bible in a spiritual sense to denote the unfaithfulness and apostasy of the Jews, because the union between God and his people was set forth as a marriage. In the N. T. "an adulterous generation" means a faithless and God-denying people.