A vow (Lat. votum, vow, promise; see vote) is a promise or oath.
Marriage vows are binding promises each partner in a couple makes to the other during a wedding ceremony. Marriage customs have developed over history and keep changing as human society develops. In earlier times and in most cultures the consent of the partners has not had the importance now attached to it, at least in Western societies and in those they have influenced.
Within the world of monks and nuns, a vow is sometimes a transaction between a person and a deity, where the former promises to render some service or gift, or devotes something valuable to the deity's use. The vow is a kind of oath, with the deity being both the witness and recipient of the promise. For example, see the Book of Judges or the Bodhisattva vows.
The god is usually expected to grant, on entering into contracts or covenants with man, the claims his vow establishes on their benevolence, and valuing of his gratitude. Conversely, in taking a vow, the petitioner's piety and spiritual attitude have begun to outweigh those merely ritual details of the ceremony that are all-important in magical rites.
Sometimes the old magical usage survives side by side with the more developed idea of a personal power to be approached in prayer. For example, in the Maghreb (in North Africa), in time of drought the maidens of Ma.zouna carry every evening in procession through the streets a doll called ghonja, really a dressed-up wooden spoon, symbolizing a pre-Islamic rain-spirit. Often one of the girls carries on her shoulders a sheep, and her companions sing the following words:
Here we have a sympathetic rain charm, combined with a prayer to the rain viewed as a personal goddess and with a promise or vow to give her the animal. The point of the promise lies of course in the fact that water is in that country stored and carried in sheep-skins.1