the person ‘vowed,’ although he still remains in the land of the living, is acquired in advance by the divinity: ‘to vow’ is a consecration and one in the most stringent form.
Benveniste establishes the vow as a form of anticipatory consecration, a binding of the living person to the deity through a rigorously formalized sequence of enunciation, formulation, reception, and fulfillment.
, Indo European Language and Society, 1973thesis