Commentaries:
Robertson's Word Pictures (NT)
Howbeit (plhn). 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 ara before eurhsei seems to indicate a question expecting a negative answer as in Acts 8:30; Romans 14:19. But here ara comes in the middle of the sentence instead of near the beginning, an unusual position for either inferential ara or interrogative ara. On the whole the interrogative ara is probably correct, meaning to question if the Son will find a persistence of faith like that of the widow.
Other Robertson's Word Pictures (NT) entries containing Luke 18:8:
Acts 25:4
Revelation 1:1
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