It is a tenet of most modern religions that you cannot bribe God or persuade him with gifts. Moreover you are limited in what you can pray for – for example you cannot pray for the humiliation of an individual you don’t like.
There were no such strictures in the religion of Ancient Greece. Here Theano the priestess prays for the downfall of Diomedes in return for twelve oxen.
ἣ δ᾽ ἄρα πέπλον ἑλοῦσα Θεανὼ καλλιπάρῃος
θῆκεν Ἀθηναίης ἐπὶ γούνασιν ἠϋκόμοιο,
εὐχομένη δ᾽ ἠρᾶτο Διὸς κούρῃ μεγάλοιο:
πότνι᾽ Ἀθηναίη ἐρυσίπτολι δῖα θεάων
ἆξον δὴ ἔγχος Διομήδεος, ἠδὲ καὶ αὐτὸν
πρηνέα δὸς πεσέειν Σκαιῶν προπάροιθε πυλάων,
ὄφρά τοι αὐτίκα νῦν δυοκαίδεκα βοῦς ἐνὶ νηῷ
ἤνις ἠκέστας ἱερεύσομεν, αἴ κ᾽ ἐλεήσῃς
ἄστύ τε καὶ Τρώων ἀλόχους καὶ νήπια τέκνα.
Theano with the beautiful cheeks took the robe and placed it on the knees of Athene with the beautiful tresses. She prayed to the daughter of great Zeus “Lady Athene, defender of the city, divine of the goddesses, break the spear of Diomedes and grant that he be thrown face down in front of the Scaean gates so that we may sacrifice at once twelve oxen, all yearlings and unbroken, in your temple if you should pity the town of Troy and the wives of the Trojans and their infant children.”
In this case Athene denied her request. Move forward a millennium or so and we still see what appears to be an attempt to give God gifts in return for answering prayers.
εἰς τοὺς ἁγίους Ἀναργύρους τοὺς εἰς τὰ Βασιλίσκου
τοῖς σοῖς θεράπουσιν ἡ θεράπαινα προσφέρω
σοφία τὸ δῶρον. χριστέ, προσδέχου τὰ σά,
καὶ τῷ βασιλεῖ μου μισθὸν Ἰουστίνῳ δίδου,
νίκας ἐπὶ νίκαις κατὰ νόσων καὶ βαρβάρων.
To the Saints Anargyroi at Basiliskos
To your servants, I, Sophia your servant, offer this gift. Christ, accept what is yours and to my emperor Justin grant as a reward victory on victory against diseases and barbarians.
Greek Anthology 1 11
Anargyroi means without silver and these saints were so called because they were doctors and treated people without payment if they were willing to convert to Christianity.