Notes on the Bible, by Albert Barnes, [1834], at sacred-texts.com
The principal things in this chapter are fully explained in Matt. 24.
What manner of stones - The stones here referred to were those used in the building of the temple, and the walls on the sides of Mount Moriah, on which the temple stood. The temple was constructed of white marble, and the blocks were of a prodigious size. Josephus says that these stones were, some of them, 50 feet long, 24 feet broad, and 16 feet in thickness.
On the mount of Olives, over against the temple - The Mount of Olives was directly east of Jerusalem, and from it there was a fine view of the temple.
Take heed to yourselves - Be cautious that no man deceive you; or, take care of your lives, not to run into unnecessary danger.
To councils - The higher ecclesiastical courts of the Jews, including the Sanhedrin, or great council of the nation.
Rulers and kings - Referring to Roman officers.
For a testimony against them - Rather to bear testimony to them, or to be witnesses "before them" of the truth. This was" for the sake" of Jesus, or because they were attached to him; and God would overrule it so that at the same time they should bear witness "to" the rulers of the truth, as was the case with Peter and John, Acts 4; with Stephen, Acts 6-7; and with Paul, Acts 23; Act 24:24-25.
Neither do ye premeditate - Do not think beforehand, or "prepare" an answer. You know not what the accusations will be, and God will furnish you with a reply that shall be adapted to the occasion.
Not ye that speak, but the Holy Spirit - This is a full promise that they should be inspired, and consequently their defenses recorded in the Acts of the Apostles are the words of the Holy Spirit. There could be no more explicit promise that they should be under an infallible guidance, and we are not left to doubt that they were taught of God. At the same time, this was a most desirable and gracious aid. They were illiterate, unknown, without power. They were unfit of themselves to make the important statements of religion which were requisite, but God gave them power, and they spake with a wisdom, fearlessness, pungency, and ability which no other men have ever manifested - full proof that these illiterate fishermen were under the influence of the Holy Spirit.
The brother shall betray ... - The brother shall give up in a treacherous manner his brother to be put to death, on account of his attachment to Jesus. Through fear, or from the hope of reward and from the hatred of the gospel, he will overcome all the natural ties of brotherhood. and give up his own kindred to be burnt or crucified. Perhaps nothing could more clearly show the dreadful evil of those times, as well as the natural opposition of the heart to the religion of Christ.
On the house-top - See the notes at Mat 9:1-8.
Neither the Son - This text has always presented serious difficulties. It has been asked, If Jesus had a divine nature, how could he say that he knew not the day and hour of a future event? In reply, it has been said that the passage was missing, according to Ambrose, in some Greek manuscripts; but it is now found in all, and there can be little doubt that the passage is genuine. Others have said that the verb rendered "knoweth" means sometimes to "make" known or to reveal, and that the passage means, "that day and hour none makes known, neither the angels, nor the Son, but the Father." It is true that the word has sometimes that meaning, as in Co1 2:2, but then it is natural to ask where has "the Father" made it known? In what place did he reveal it? After all, the passage has no more difficulty than that in Luk 2:52, where it is said that Jesus increased in wisdom and stature. He had a human nature. He grew as a man in knowledge. As a man his knowledge must be finite, for the faculties of the human soul are not infinite. As a man he often spoke, reasoned, inquired, felt, feared, read, learned, ate, drank, and walked. Why are not all these, which imply that he was a "man" - that, "as a man," he was not infinite - why are not these as difficult as the want of knowledge respecting the particular "time" of a future event, especially when that time must be made known by God, and when he chose that the man Christ Jesus should grow, and think, and speak "as a man?"
Who left his house - The word "house" often means family. Our Saviour here represents himself as going away, leaving his household the church, assigning to the apostles and all his servants their duty, and leaving it uncertain when he would return. Since his return was a matter of vast consequence, and as the affairs of his kingdom were entrusted to them, just as the affairs of a house are to servants when the master is absent, so it was of vast importance that they should be faithful at their post, that they should defend the house from danger, and be ready for his return.
The porter - The doorkeeper. To the janitor or doorkeeper was entrusted particularly the care of the house, whose duty it was to attend faithfully on those who came and those who left the house.
Watch ye - Be diligent, faithful, and waiting for the return of your Lord, who will come at an unexpected hour.
Master of the house - Denoting here the Lord Jesus.
At even, or at midnight, or ... - This refers to the four divisions into which the Jews divided the night.
Find you sleeping - Inattentive to your post, neglecting your duty, and unprepared for his coming.
I say unto all, Watch - This command was proper, not only for those who were expecting the calamities that were soon to come upon the Jews, but for all who are soon to die and to go to the judgment. We know not the time of our death. We know not how soon we shall be called to the judgment. The Son of man may come at any moment, and we should therefore be ready. If we are his friends; if we have been renewed and pardoned; if we have repented of our sins, and have believed on him. and are leading a holy life, we "are" ready. If not, we are unprepared, and soon - probably while we are not expecting it - the cold hand of death will be laid on us, and we shall be hurried to the place where is weeping, and wailing, and gnashing of teeth. Oh how important it is to be ready, and to escape the awful sufferings of an eternal hell!