A.T. Robertson Commentary Luke 18:8

"I say unto you, that he will avenge them speedily. Nevertheless, when the Son of man cometh, shall he find faith on the earth?" — Luke 18:8 (ASV)

Howbeit (πλην). It is not clear whether this sentence is also a question or a positive statement. There is no way to decide. Either will make sense though not quite the same sense. The use of αρα before ευρησε seems to indicate a question expecting a negative answer as in Ac 8:30; Romans 14:19. But here αρα comes in the middle of the sentence instead of near the beginning, an unusual position for either inferential αρα or interrogative αρα. On the whole the interrogative αρα is probably correct, meaning to question if the Son will find a persistence of faith like that of the widow.