William Burkitt on Matthew 24:42

Here we have the application made by our Saviour, of the foregoing doctrine concerning the certainty and suddenness of a future judgment. Watch therefore, always; not without intermission, but without giving over; that ye may be not only in an habitual but actual readiness for my appearance.

Learn hence, That it is the indispensable duty, and ought to be the indefatigable endeavour of every Christian, to stand upon his watch in a prepared readiness for Christ's appearance, both for his coming to us, and for our going to him.

Watch always, for ye know not the hour when our Lord cometh!