As the whirlwind passeth. According to this rendering (which has the support of the Vulgate) the idea is the speed with which, under God's vengeance, the sinner is consumed, as Isaiah 17:13; Job 21:18.
But it is better to translate, as the LXX; "when the whirlwind is passing," i.e. when the storm of judgment falls, as Christ represents the tempest beating on the ill-founded house and destroying it, while that which was built on the rock remains uninjured (comp.
Proverbs 12:3; Matthew 7:25, etc.; comp. Wis. 5:14, etc). Everlasting foundation (Job 21:30; Psalms 91:1-16; Psalms 125:1); like the Cyclopean stones on which Solomon's temple was built. It is natural to see here an adumbration of that Just One, the Messiah, the chief Cornerstone.
The LXX. gives, "But the righteous turning aside is saved forever."