ḥoten

This is the word used as a title for a relative gained through marriage, and it always points to the wife's side of the family. When the Bible calls someone a man's father-in-law with this word, it means the father of the woman he married, the man who gave his daughter to him. Jethro, whose daughter Zipporah married Moses, is the stock example: the story of Exodus repeats the title again and again.

Biblical Hebrew is careful about which side of a marriage a relative belongs to. This word names the wife's father specifically, never the husband's father, who is called by a different word. Its feminine form names the wife's mother in the same way. English blurs these lines by wrapping them all in the single phrase "in-law," so the precise family map behind the Hebrew is easy to miss.

The title reflects a real bond, not just a legal label. A father-in-law hosts his son-in-law, advises him, sends him off with a blessing, and shares meals and sacrifices with him, as Jethro does with Moses. The same warmth and obligation appear in the account of the Levite and the young woman's father in Judges.

This is the action behind the family titles: to enter into kinship with someone by marriage, so that two households or two peoples become bound to each other. It can describe whole groups linking up, as when one nation marries into another, or a single man marrying into a particular family and so becoming its son-in-law.

At the level of peoples, the word carries the weight of an alliance. When Israel is warned not to do this with the nations already in the land, the concern is not skin or ancestry but loyalty: marrying into peoples who serve other gods would pull Israel's heart away from the LORD. Solomon's marriage to Pharaoh's daughter and Jehoshaphat's tie to the house of Ahab are alliances of exactly this kind, sealed by a wedding but political at their core.

At the level of a single person, the word describes a man marrying into a family and taking his place in it. The clearest case is David, whom Saul repeatedly presses to become the king's son-in-law by marrying his daughter, a step that would bind David to the royal house.