Luke 18:1

1He was speakingἜλεγενthenδὲa parableπαραβολὴνto themαὐτοῖςaboutπρὸςthe [way]τὸit behoovesδεῖνalwaysπάντοτεto prayπροσεύχεσθαιthemαὐτοὺςandκαὶnotμὴto lose heartἐγκακεῖν,

And He was speaking a parable to them that it is necessary for them always to pray and not to grow fainthearted,