Because He had been giving high and lofty precepts, immediately follows the comparison of building a tower, when it is said, For which of you intending to build a tower does not first count &c. For every thing that we do should be preceded by anxious consideration. If then we desire to build a tower of humility, we ought first to brace ourselves against the ills of this world.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: 37. in Ev.