Verse 5. Ye are all the children of light. All who are Christians. The phrase "children of light" is a Hebraism, meaning that they were the enlightened children of God.

And the children of the day. Who live as if light always shone round about them. The meaning is, that in reference to the coming of the Lord, they are as men would be in reference to the coming of a thief, if there were no night, and no necessity of slumber. They would always be wakeful and active, and it would be impossible to come upon them by surprise. Christians are always to be wakeful and vigilant; they are so to expect the coming of the Redeemer, that he will not find them off their guard, and will not come upon them by surprise.