Christ bases His command on our ignorance of the time of His coming. It was no part of His purpose in this prophecy to remove that ignorance, and no calculations of the chronology of unfulfilled predictions have pierced the darkness. It was His purpose that from generation to generation His servants should be kept in the attitude of expectation, as of an event that may come at any time and must come at some time. The parallel uncertainty of the time of death, though not what is meant here, serves the same moral end if rightly used, and the fact of death is exposed to the same danger of being neglected because of the very uncertainty, which ought to be one chief reason for keeping it ever in view. Any future event, which combines these two things, absolute certainty that it will happen, and utter uncertainty when it will happen, ought to have power to insist on being remembered, at least, till it was prepared for, and would have it, if men were not such fools. Christ's coming would be oftener contemplated if it were more welcome. But what sort of a servant is he, who has no glow of gladness at the thought of meeting his lord? True Christians are 'all them that have loved His appearing.'
The illustrative example which separates these two commands is remarkable. The householder's ignorance of the time when the thief would come is the reason why he does not watch. He cannot keep awake all night, and every night, to be ready for him; so he has to go to sleep, and is robbed. But our ignorance is a reason for wakefulness, because we can keep awake all the night of life. The householder watches to prevent, but we to share in, that for which the watch is kept. The figure of the thief is chosen to illustrate the one point of the unexpected stealthy approach. But is there not deep truth in it, to the effect that Christ's coming is like that of a robber to those who are asleep, depriving them of earthly treasures? The word rendered 'broken up' means literally 'dug through,' and points to a clay or mud house, common in the East, which is entered, not by bursting open doors or windows, but by digging through the wall. Death comes to men sunk in spiritual slumber, to strip them of good which they would fain keep, and makes his entrance by a breach in the earthly house of this tabernacle. So St. Paul, in his earliest Epistle, refers to this saying (a proof of the early diffusion of the gospel narrative), and says, 'Ye, brethren, are not in darkness, that that day should overtake you as a thief.'
II. The picture and reward of watchfulness. The general exhortation to watch is followed by a pair of contrasted parable portraits, primarily applicable to the apostles and to those 'set over His household.' But if we remember what Christ taught as the condition of pre-eminence in His kingdom, we shall not confine their application to an order.
'The least flower with a brimming cup may stand, And share its dew-drop with another near,'
and the most slenderly endowed Christian has some crumb of the bread of life intrusted to him to dispense. It is to be observed that watchfulness is not mentioned in this portraiture of the faithful servant. It is presupposed as the basis and motive of his service. So we learn the double lesson that the attitude of continual outlook for the Lord is needed, if we are to discharge the tasks which He has set us, and that the true effect of watchfulness is to harness us to the car of duty. Many other motives actuate Christian faithfulness, but all are reinforced by this, and where it is feeble they are more or less inoperative. We cannot afford to lose its influence. A Church or a soul which has ceased to be looking for Him will have let all its tasks drop from its drowsy hands, and will feel the power of other constraining motives of Christian service but faintly, as in a half-dream.