Ye shall hear ... — Literally, ye shall be about to hear — a kind of double future, or possibly an example of the transition between the older future tense and the use of an auxiliary verb.
Wars and rumours. — St. Luke adds “commotions.” The forty years that intervened before the destruction of Jerusalem were full of these in all directions; but we may probably think of the words as referring specially to wars, actual or threatened, that affected the Jews, such, e.g., as those of which we read under Caligula, Claudius, and Nero (Jos. Ant. xx. 1, 6). The title which the historian gave to his second book, “The Wars of the Jews,” is sufficiently suggestive. As the years passed on, the watchword, “Be not troubled,” must have kept the believers in Christ calm in the midst of agitation. They were not to think that the end was to follow at once upon the wars which were preparing the way for it.