Luke 17:7 - Ellicott's Commentary On The Whole Bible

But which of you, having a servant..? — The words contain in reality, though not in form, an answer to their question. They had been asking for faith, not only in a measure sufficient for obedience, but as excluding all uncertainty and doubt. They were looking for the crown of labour before their work was done, for the wreath of the conqueror before they had fought the battle. He presses home upon them the analogies of common human experience. The slave who had been “ploughing” or “feeding sheep” (the word is that always used of the shepherd’s work, as in John 21:16; Acts 20:28; 1 Peter 5:2, and so both the participles are suggestive of latent parables of the spiritual work of the Apostles) is not all at once invited to sit down at the feast. He has first to minister to his master’s wants, to see that his soul is satisfied, and then, in due course, his own turn will come. So, in the life of the disciples, outward ministerial labour was to be followed by personal devotion. In other words, the “increase of faith” for which the Apostles prayed, was to come through obedience, outward and inward obedience, to their Master’s will. Faith was to show itself in virtue, and virtue would bring knowledge, and knowledge would strengthen faith. Comp. 2 Peter 1:5, as showing that the lesson had been learnt.