Luke 21:29

Here, in the close of this discourse, I. Christ appoints his disciples to observe the signs of the times, which they might judge by, if they had an eye to the foregoing directions, with as much certainty and assurance as they could judge of the approach of summer by the budding forth of the trees, Luk 21:29-31. As in the kingdom of nature there is a chain of causes, so in the kingdom of providence there is a consequence of one event upon another. When we see a nation filling up the measure of their iniquity, we may conclude that their ruin is nigh; when we see the ruin of persecuting powers hastening on, we may thence infer that the kingdom of God is nigh at hand, that when the opposition given to it is removed it shall gain ground. As we may lawfully prognosticate the change of the seasons when second causes have begun to work, so we may, in the disposal of events, expect something uncommon when God is already raised up out of his holy habitation (Zac 2:13); then stand still and see his salvation. II. He charges them to look upon those things as neither doubtful nor distant (for then they would not make a due impression on them), but as sure and very near. The destruction of the Jewish nation, 1. Was near (Luk 21:32): This generation shall not pass away till all be fulfilled.

— Matthew Henry's Concise Commentary (public domain)