Matthew 24:30

30Andκαὶthenτότεwill appearφανήσεταιtheτὸsignσημεῖονof theτοῦSonυἱοῦτοῦof Manἀνθρώπουinἐνtheτῷheavenοὐρανῷ,andκαὶthenτότεwill mournκόψονταιallπᾶσαιtheαἱtribesφυλαὶof theτῆςearthγῆςandκαὶthey will seeὄψονταιtheτὸνSonυἱὸντοῦof Manἀνθρώπουcomingἐρχόμενονonἐπὶtheτῶνcloudsνεφελῶντοῦof heavenοὐρανοῦwithμετὰpowerδυνάμεωςandκαὶgloryδόξηςgreatπολλῆς·

And then the sign of the Son of Man will appear in heaven, and then all the tribes of the earth will mourn. And they will see the Son of Man coming on the clouds of heaven, with power and great glory.