Matthew 12:40

40Just asὥσπερforγὰρwasἦνJonahἸωνᾶςinἐνtheτῇbellyκοιλίᾳof theτοῦgreat fishκήτουςthreeτρεῖςdaysἡμέραςandκαὶthreeτρεῖςnightsνύκτας,soοὕτωςwill beἔσταιtheὁSonυἱὸςτοῦof Manἀνθρώπουinἐνtheτῇheartκαρδίᾳof theτῆςearthγῆςthreeτρεῖςdaysἡμέραςandκαὶthreeτρεῖςnightsνύκτας.

For just as Jonah was in the belly of the great fish three days and three nights, so the Son of Man will be in the heart of the earth three days and three nights.