John Calvin Commentary Matthew 24:44

"Therefore be ye also ready; for in an hour that ye think not the Son of man cometh." — Matthew 24:44 (ASV)

But know this. Another illustration is now employed by Christ in exhorting His disciples to keep diligent watch. For if anyone hears that robbers are prowling in the night, fear and suspicion will not allow him to sleep.

Since, therefore, we are informed that Christ’s coming will be sudden and unexpected, like that of a robber, and since we are expressly forewarned that we must always watch lest He come upon us when asleep and we be swallowed up with the ungodly, there is no excuse for our indolence.

Indeed, there is reason to dread not only a breach of the wall and a loss of our property, but a deadly wound to ruin our soul, unless we are on our guard.

The purpose of these words, therefore, is that Christ’s warning should arouse us. For though the last judgment may be delayed for a long time, yet it hangs over us every hour; and therefore, when there is ground for alarm and when danger is near, it is unreasonable for us to be sluggish.