A Crow was caught but released by Apollo on promise of an offering. The offering was never made so when the Crow as again captured no other god helped.
Lie once and you may not be believed later.
Townsend version
A crow caught in a snare prayed to Apollo to release him, making a vow to offer some frankincense at his shrine. But when rescued from his danger, he forgot his promise. Shortly afterwards, again caught in a snare, he passed by Apollo and made the same promise to offer frankincense to Mercury. Mercury soon appeared and said to him, “O thou most base fellow? how can I believe thee, who hast disowned and wronged thy former patron?’
Corvus et Mercurius
Corvus, laqueo captus, Apollinem ut opem ferret precabatur, se ei tus oblaturum pollicitus. Sed, a periculo liberatus, promissi oblitus est. Rursus autem cum in laqueum incidisset, Apolline omisso, sacrificaturum se Mercurio vovit. At ille, “O pessime,” ait, “quomodo credam tibi, qui priorem, a quo servatus es, illusisti atque laesisti?”
Moral
Qui in beneficos ingrati sunt, in calamitates ubi inciderint, nullum auxilium nanciscuntur.
Perry #323
