b—
Sacrifice to Apollo (402–47)
After the launch, the Argonauts offer sacrifice to Apollo in accordance with Jason's instructions. To summarize the action: the men build an altar to Apollo under his cult titles Actius and Embasius. Attendants then bring two cows and the sacred implements
to the place of sacrifice (402–10). Jason prays to Apollo for a safe return to Greece under his personal guidance, which the god had promised at Delphi, and then vows further sacrifices upon their return (411–24). Heracles and Ancæus each slaughter an animal, the former with his club, the latter with his axe. The men prepare and roast the meat, and Jason pours the libation; and Idmon, who observes the signs in the flame that reveal Apollo's approval (425–38), then announces to all his favorable interpretation, predicting his own death. The Argonauts respond appropriately to the good news with joy but to the bad with grief (439–49).
Vian notes Apollonius's dependence on Homeric sacrificial practice in his presentation of the sacrifice to Apollo, and points out that the passage has special reference to one scene in particular: the sacrifice to Athena celebrated in Pylos at the home of Nestor as described in the Odyssey .[32] Two details stand out in particular. First, Apollonius gives a close rendition of three lines:
and the rest
brought holy water and barley meal . Next 
,
calling on 
, the protector of his ancestors, offered prayer :
The aged knight 
began the rite with holy water and barley meal , and as a beginning
he offered many a prayer to 
, tossing the hair of its head
into the fire.
Second, the same number of men are involved in the act of killing the animals. In the Odyssey , the Pylians sacrifice only one cow, but two men perform the immolation: Thrasymedes strikes it with an axe (the same tool used by Ancæus), and Peisistratus cuts its throat (Od. 3.447–54). In the Argonautica , there are two cows (the same number of cows slaughtered by Hermes in the Homeric hymn), and Apollonius provides two men to slaughter them, Heracles and Ancæus (425–31). One can add to these two similarities the fact that the Odyssean sacrifice, like its Argonautic imitation, precedes a journey, that of Telemachus to Sparta, where he hopes to learn of his father's fate from Menelaus. These shared features call attention to what I believe is the most important point of contact. At the end of the previous day Athena had advised all to go to sleep after pouring a libation over the tongues (Od. 3.332–36), a passage alluded to at the conclusion of this episode (see below). After this, Nestor invites Telemachus and Athena in her disguise as Mentor to stay. Athena refuses, and as she departs transforms herself into a bird (371–73). Nestor responds to this miraculous event by stating:
O friend, I do not think that you will turn out to be cowardly
and weak,
if in your youth the gods accompany you as your guides.
What marks Telemachus out as special is a sign that the gods personally guide him along his path. It is in response to this sign that Nestor vows the sacrifice of a cow with gilded horns, the sacrifice that Apollonius has in mind when describing that of the Argonauts to Apollo.
Just prior to the slaughter of the two cows, Jason asked specifically for personal guidance from the divinity who commissioned the expedition:
Hear, O Lord, you who dwell in Pagasae and the city of Æsonis,
named after our father; you who promised when I consulted your
oracle
at Pytho to reveal to me how I would accomplish the goals
of my journey; you who were responsible for this expedition:
you yourself now guide the ship there and back again to Greece
with my comrades unharmed.
Apollonius reveals in two ways, directly and indirectly, that Apollo has heard and assented to Jason's prayer. The poet has Idmon explicitly confirm his father's consent with his reading of the murky flame, which he characterizes as 
(438). But the good will of the god is also to be inferred from the clear reference to the Odyssean sacrifice that Nestor offered to a divinity who acted as personal guide for the youthful Telemachus. In short, Jason prayed for personal guidance, and the sacrifice following this prayer alludes to a sacrifice offered in response to a god's personal guidance. The explicit sign was for Jason; but there is an implicit sign, as well, and this sign is for the doctus lector .
In the course of his travels to Colchis and back, Jason will in fact receive personal assistance from several divinities, among whom Apollo will play an important role, especially in his celebrated epiphany to the Argonauts near the island of Anaphe.[34] At Anaphe a thick mist will envelop the heroes during the night, and Apollo will appear in person to illuminate their way to safety (cf. 4.1694–1730). This will be the climactic obstacle to the completion of their 
. Callimachus dealt with the same episode
near the beginning of Book 1 of the Ætia (fr. 7–21 Pf.). As Pfeiffer noted (ad fr. 18.6–15), Apollonius in this passage is imitating Jason's vow to sacrifice to Apollo on his return in Callimachus's poem:[35]
For you thereafter
we shall offer again on this altar as many splendid bulls
in sacrifice as there are those of us who have returned. I shall
bring countless other gifts to Pytho , still others to Ortygia .
the Tyndaridae
they approached Zeus first
they asked the other immortals
who would help the ship of excellent keel
But the son of Æson, with anguish in his soul
raised his hands to you, Ieius, and promised to send
many gifts to Pytho , and many to Ortygia ,
if you dispersed the murky cloud from the ship.
that, in accordance with your oracle, Phoebus[*] ,
they untied the cables and divided up the oars
they struck the bitter waters
named after the god of embarkation
at Pagasae
If Apollonius is in fact the imitator here and wants the reader to recall his model, then just as happens in the reference to Nestor's sacrifice to Athena in Odyssey 3, the allusion has the effect of confirming Apollo's acceptance of Jason's prayer. The verbal reminiscence of the Anaphe episode in Callimachus's Ætia causes the reader to think of the climactic moment of the expedition, when Apollo provided his personal assistance. Moreover, Apollonius will repeat his imitation of these Callimachean lines just before Apollo will make good his promise to assist Jason in person (4.1704–5).