The term pilegesh comes from a non-Hebrew, non-Semitic loanword deriving from the Greek word pallakis, Greek παλλακίς, meaning a mistress staying in house; there is a common but unfounded view that it derives from the Aramaic phrase palga isha, meaning half-wife.
In contemporary Israeli Hebrew, the word "pilegesh" is often used as the equivalent of English "mistress"—i.e. the female partner in extramarital relations even when these relations have no legal recognition.
Biblical references 
Several biblical figures had concubines when they were not able to create natural children with their wives. The most famous example of this was with Abraham and Sarah. Sarah, feeling guilty about her inability to give Abraham children, gave her maidservant Hagar to Abraham. Their union produced Ishmael.
A pilegesh was recognized among the ancient Hebrews and enjoyed the same rights in the house as the legitimate wife. Since having children in Judaism was considered a great blessing, legitimate wives often gave their maids to their husbands so they could have children with them when those women themselves where childless, normally because of infertility issues as in the cases of Sarah and Hagar; Leah and Zilpah; and Rachel and Bilhah. The concubine commanded the same respect and inviolability as the wife, and it was regarded as the deepest dishonor for the man to whom she belonged if hands were laid upon her.
Among the Israelites, men commonly acknowledged their concubines, and such women enjoyed the same rights in the house as legitimate wives. The principal difference in the Bible between a wife and a concubine is that wives had dowries, while concubines did not.
The concubine may have commanded the same respect and inviolability as the wife. The Hebrew word used in the Levitical rules on sexual relations, which is commonly translated as "wife", is distinct from the Hebrew word that means "concubine". (However, on at least one other occasion it is used to refer a woman who is not a wife - specifically, the handmaid of Jacob's wife.) In the Levitical code, sexual intercourse between a man and a wife of a different man was forbidden and punishable by death for both persons involved. The Bible notes several incidents of intercourse between a man and another man's concubine, and none of them result in capital punishment for either party, although the man to whom the concubine belonged was dishonored by such a relationship. For instance, David is portrayed as having been dishonoured when his concubines had a sexual relationship with his son Absalom. However, this instance is as likely dishonoring to David because it involves a form of incest, as David's concubines would have been somewhat like step-mothers to David's children.
Since it was regarded as the highest blessing to have many children, legitimate wives often gave their maids to their husbands to atone, at least in part, if they were barren, as in the cases of Sarah and Hagar, Rachel and Bilhah. The children of the concubine had equal rights with those of the legitimate wife; for example, King Abimelech was the son of Gideon and his concubine. Later biblical figures such as Gideon, David, and Solomon had concubines in addition to many childbearing wives. For example, the Books of Kings says that Solomon had 700 wives and 300 concubines; the wives were royal princesses with dowries, while concubines had no dowries..
Legal characteristics 
According to the Babylonian Talmud (Sanh. 21a), the difference between a pilegesh and a full wife was that the latter received a marriage contract (Hebrew:ketubah) and her marriage (nissu'in) was preceded by a formal betrothal ("kiddushin"), which was not the case with the former. According to R. Judah, however, the pilegesh should also receive a marriage contract, but without including a clause specifying a divorce settlement.
Certain Jewish thinkers, such as Maimonides, believed that concubines are strictly reserved for kings, and thus that a commoner may not have a concubine; indeed, such thinkers argued that commoners may not engage in any type of sexual relations outside of a marriage. Before Maimonides concluded this, Sunni Muslims officially prohibited mutah (i.e. temporary marriage) relationships; some commentators'[who?] suggest that Maimonides changed his view in response to this development, similar to Gershom ben Judah's ban on polygamy being made after Christians had prohibited it.
Maimonides was not the first Jewish thinker to criticise concubinage; for example, it is severely condemned in Leviticus Rabbah. Other Jewish thinkers, such as Nahmanides, Samuel ben Uri Shraga Phoebus, and Jacob Emden, strongly object to the idea that concubines should be forbidden.
In the Hebrew of the contemporary State of Israel, the word pilegesh is often used as the equivalent of the English word, mistress—i.e. the female partner in extramarital relations, regardless of legal recognition. Attempts to popularise pilegesh as a form of premarital, non-marital and extramarital relationships (which, according to the perspective of the enacting person/s, is permitted by Jewish law have been initiated.
Any offspring created as a result of a union between a pilegesh and a man were on equal legal footing with children of the man and his wife.
Rambam (Maimonides) held that concubines were prohibited under Jewish law. He wrote that concubines were reserved for kings and sexual relations outside of marriage was not permitted. Ramban (Nahmanides), Shmuel ben Uri, and Yaakov Emden disagreed.
It has been suggested that Rambam's published view was meant to shape a public policy in response to the prohibition of mut'ah relationships by Sunni Muslims, which are in many ways similar to pilegesh relationships, just as the ban on polygamy by Rabbeinu Gershom was made only subsequently to the Christian prohibition of it that effectively changed the law of the land.
See also 
- Michael Lieb, Milton and the culture of violence, p. 274, Cornell University Press, 1994
- Marc Lee Raphael, Agendas for the study of Midrash in the twenty-first century, p. 136, Dept. of Religion, College of William and Mary, 1999
- Nicholas Clapp, Sheba: Through the Desert in Search of the Legendary Queen, p. 297, Houghton Mifflin, 2002
- Staff (2002-2011). "PILEGESH (Hebrew, ; comp. Greek, παλλακίς).". Jewish Encyclopedia. JewishEncyclopedia.com. Retrieved 13 June 2012.
- Genesis 30:4
- Leviticus 20:10
- Deuteronomy 22:22
- 2 Samuel 3:7
- 2 Samuel 16:22
- Judges 19:2
- 2 Samuel 16:21-25
- Leviticus 20:11
- Judges 8:31
- 1 Kings 11:1-3
- Leviticus Rabbah, 25
- MATTHEW WAGNER (16 March 2006). "Kosher sex without marriage". The Jerusalem Post. Retrieved 13 June 2012.
- Adam Dickter, "ISO: Kosher Concubine", New York Jewish Week, December 2006
- SUZANNE GLASS, "THE CONCUBINE CONNECTION", The Independent, London 20 October 1996
- Between Civil and Religious Law: The Plight of the Agunah in American Society, Irving Breitowitz, Greenwood Press, 1993. By coincidence, Breitowitz's book was reviewed by Risikoff's grandson, Rabbi Steven Resnicoff, in Jewish Action, Winter 1994, Vol. 55, No. 2.
- Kosher sex without marriage Jpost By Mathew Wagner
- "ISO: Kosher Concubine" New York Jewish Week by Adam Dickter December 2006
- The Concubine Connection The Independent, London, October 20, 1996, Suzanne Glass