When He spoke about preaching, and called it a sword, His hearers may have been troubled, not knowing what He meant. And therefore our Lord adds, that as men determine the state of the weather by certain signs, so ought they to know His coming. And this is what he means by saying, When ye see a cloud rise out of the west, straightway ye say, There cometh a shower. And when ye see the south wind blowing, ye say, There will be heat, &c. As if He says, Your words and works shew me to be opposed to you. Ye may therefore suppose that I came not to give peace, but the storm and whirlwind. For I am a cloud, and I come out of the west, that is, from human nature; which has been long since clothed with the thick darkness of sin. I came also to send fire, that is, to stir up heat. For I am the strong south wind, opposed to the northern coldness.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).