‘And as they heard these things, he added and spoke a parable, because he was near to Jerusalem, and because they supposed that the Kingly Rule of God was immediately to appear.'
The loose connection confirms that this passage is attached to the previous one, but is vague enough to otherwise give us no information as to when it was given. It is clear, however, that we are to see it as spoken just prior to His approach to Jerusalem in order to correct the wrong impression that His arrival there will result in the final appearance of the everlasting Kingly Rule of God on earth (a belief that the Apostles clung to until the descent of the Holy Spirit at Pentecost - Acts 1:6).
It is understandable that, with His constant references to the importance of His approach to Jerusalem (Luke 9:31; Luke 13:33; Luke 18:31), together with His no doubt clearly revealed urgency about that approach, and the unwillingness of His followers to believe the worst, they had gained the wrong impression about it, in spite of His efforts to ensure that it was otherwise. They had probably interpreted His statements about His coming death and resurrection metaphorically in terms of the hard earthly battle that lay ahead whereby He would overcome the opposition of the Jewish leaders, seize Jerusalem, and commence the process which would result in final triumph. In principle they were right. Spiritually that was what would happen as Acts reveals. It was on how this was to be brought about, and the timescale involved, that they had got it totally wrong. This parable was an attempt to correct at least part of that error.
So He stresses His departure to a ‘far country' to receive His Kingship, the fact that His absence will be sufficient for someone to multiply an investment manyfold, and meanwhile that there will be attempts by some to prevent the establishment of His Kingly Rule. It makes it clear therefore that His appearance as King will not be within the too near future.