He means the generation not only of the Jews, but also of all wicked men, by whom even now in His own body, that is, His Church, the Son of man suffers many things, and is rejected. But while He spake many things of His coming in glory, He inserts something also concerning His Passion, that when men saw Him dying, whom they had heard would be glorified, they might both soothe their sorrow for His sufferings by the hope of the promised glory, and at the same time prepare themselves, if they love the glories of His kingdom, to look without alarm upon the horrors of death.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).