Propitiation and Sacrifice
Propitiation and sacrifice, to avoid such visitation would be the natural outcome, and the various traditions are probably records of actual occurrences, embroidered by poetic imagery and miraculous conditions.
In later tradition, cause or justification is indicated as in the story of Iphigenia, daughter of Clytemnestra and Agamemnon. The latter having offended Artemis by killing her favourite stag, vowed to sacrifice the most beautiful thing that came into his possession during the next twelve months. This was an infant daughter, but the sacrifice was deferred till she reached womanhood, when the combined Greek fleet arrived at Aulis on its way to Troy. Calchas declared this would be wind-bound as long as the vow remained unfulfilled, but Artemis interposed at the last moment by spiriting Iphigenia away from the altar and leaving a hind to suffer in her stead.
A similar story is that of Andromeda, rescued by Perseus from the sea monster sent by Poseidon to devastate the land. The reputed cause was Cassiopeia, mother of Andromeda, boasting of her daughter’s beauty, and on appeal to the oracle the sacrifice was declared necessary to save the country and to appease the offended deity.
Similar instances in Bible history are the vows of sacrifice made by Abraham and Jephthah. The latter has a parallel in the Greek tradition of Idomeneus, King of Crete, who vowed to sacrifice the first being he encountered if the gods granted him a safe return after the burning of Troy. The first person met on landing was his son, who was sacrificed, and in consequence Idomeneus was banished as a murderer.