Are there not twelve hours in the day? This passage has been explained in various ways. Some have thought the meaning of these words to be, that men sometimes adopt a new and different resolution every hour. This is very far from Christ's meaning; and indeed I would not have reckoned it worthy of being mentioned, had it not been that it has passed into a common proverb. Let us therefore be satisfied with the simple and natural meaning. First, Christ borrows a comparison from Day and Night. For if any man perform a journey in the dark, we need not wonder if he frequently stumble, or go astray, or fall; but the light of the sun by day points out the road, so that there is no danger. Now the calling of God is like the light of day, which does not allow us to mistake our road or to stumble. Whoever, then, obeys the word of God, and undertakes nothing but according to his command, always has God to guide and direct him from heaven, and with this confidence he may safely and boldly pursue his journey. For, as we are informed, Whosoever walketh in his ways hath angels to guard him, and, under their direction, is safe, so that he cannot strike his foot against a stone, (Psalm 91:11.) Relying on this protection, therefore, Christ advances boldly into Judea, without any dread of being stoned; for there is no danger of going astray, when God, performing the part of the sun, shines on us, and directs our course. We are taught by these words, that whenever a man allows himself to be guided by his own suggestions, without the calling of God, his whole life is nothing else than a course of wandering and mistake; and that they who think themselves exceedingly wise, when they do not inquire at the mouth of God, and have not his Spirit to govern their actions, are blind men groping in the dark; that the only proper way is, to be fully assured of our divine calling, and to have always God before our eyes as our guide. [1] This rule of regulating our life well is followed by a confident expectation of a prosperous result, because it is impossible that God shall not govern successfully. And this knowledge is highly necessary to us; for believers can scarcely move a foot to follow him, but Satan shall immediately interpose a thousand obstructions, hold out a variety of dangers on every side, and contrive, in every possible way, to oppose their progress. But when the Lord invites us to go forward, by holding out, as it were, his lamp to us, we ought to go forward courageously, though many deaths besiege our path; for he never commands us to advance without at the same time adding a promise to encourage us, so that we may be fully convinced, that whatever we undertake agreeably to his command will have a good and prosperous issue. This is our chariot, and whoever betakes himself to it will never fail through weariness; and even though the obstacles were so formidable that we could not be conveyed through them by a chariot, yet, furnished with these wings, we shall always succeed, till we reach the goal. Not that believers never meet with any adversity, but because adverse occurrences are aids to their salvation. It amounts to this, that the eyes of God will always be attentive to guard those who shall be attentive to his instructions. Hence we learn also that, whenever men overlook and disregard the word of God, and consequently indulge themselves foolishly, and undertake whatever they think right, the whole course of their life is accursed by God, and vengeance is always ready to punish their presumption and their blind passions. Again, Christ here divides the day into twelve hours, according to ancient custom; for though the days are longer in summer and shorter in winter, [2] yet they had always twelve hours of the day, and twelve of the night.

Footnotes

1 - "Quand nous avons tousjours Dieu devant nos yeux pour nostre guide."

2 - "Combien que les jours soyent plus grands en este, et plus petits en hyver."

Twelve hours - The Jews divided the day from sunrise to sunset into twelve equal parts. A similar illustration our Saviour uses in John 9:4-5. See the notes at that place.
If any man walk - If any man travels. The illustration here is taken from a traveler. The conversation was respecting a journey into Judea, and our Lord, as was his custom, took the illustration from the case before him.
He stumbleth not - He is able, having light, to make his journey safely. He sees the obstacles or dangers and can avoid them.
The light of this world - The light by which the world is illuminated that is, the light of the sun.
In the night - In darkness he is unable to see danger or obstacles, and to avoid them. His journey is unsafe and perilous, or, in other words, it is not a proper time to travel.
No light in him - He sees no light. It is dark; his eyes admit no light within him to direct his way. This description is figurative, and it is difficult to fix the meaning. Probably the intention was the following:
1. Jesus meant to say that there was an allotted or appointed time for him to live and do his Father's will, represented here by the 12 hours of the day.
2. Though his life was nearly spent, yet it was not entirely; a remnant of it was left.
3. A traveler journeyed on until night. It was as proper for him to travel the twelfth hour as any other.
4. So it was proper for Jesus to labor until the close. It was the proper time for him to work. The night of death was coming, and no work could then be done.
5. God would defend him in this until the appointed time of his death. He had nothing to fear, therefore, in Judea from the Jews, until it was the will of God that he should die. He was safe in his hand, and he went fearlessly into the midst of his foes, trusting in him. This passage teaches us that we should be diligent to the end of life: fearless of enemies when we know that God requires us to labor, and confidently committing ourselves to Him who is able to shield us, and in whose hand, if we have a conscience void of offence, we are safe.

Are there not twelve hours in the day? - The Jews, as well as most other nations, divided the day, from sun-rising to sun-setting, into twelve equal parts; but these parts, or hours, were longer or shorter, according to the different seasons of the year. See the note on John 1:39. Our Lord alludes to the case of a traveler, who has to walk the whole day: the day points out the time of life - the night that of death. He has already used the same mode of speech, John 9:4 : I must work the works of him that sent me, while it is day: the night cometh when no man can work. Here he refers to what the apostles had just said - The Jews were but just now going to stone thee. Are there not, said he, twelve hours in the day? I have not traveled these twelve hours yet - my last hour is not yet come; and the Jews, with all their malice and hatred, shall not be able to bring it a moment sooner than God has purposed. I am immortal till my work is done; and this, that I am now going to Bethany to perform, is a part of it. When all is completed, then their hour, and that of the power of darkness, shall commence. See Luke 22:53.
If any man walk in the day, he stumbleth not - A traveler should use the day to walk in, and not the night. During the day he has the sun, the light of this world: he sees his way, and does not stumble: but, if he walk in the night, he stumbleth, because there is no light in it, John 11:10; i.e. there is no sun above the horizon. The words εν αυτῳ, John 11:10, refer not to the man, but to the world, the sun, its light, not being above the horizon. Life is the time to fulfill the will of God, and to prepare for glory. Jesus is the light of the world; he that walks in his Spirit, and by his direction, cannot stumble - cannot fall into sin, nor be surprised by an unexpected death. But he who walks in the night, in the darkness of his own heart, and according to the maxims of this dark world, he stumbles - falls into sin, and at last falls into hell. Reader! do not dream of walking to heaven in the night of thy death. God has given thee the warning: receive it, and begin to live to him, and for eternity.

Jesus answered, Are there not (c) twelve hours in the day? If any man walk in the day, he stumbleth not, because he seeth the light of this world.
(c) All things happen in a proper way and are brought to pass in their due time.

Jesus answered, are there not twelve hours in the day?.... So the Jews reckoned, and so they commonly say (a), , "twelve hours are a day", or a day consists of twelve hours, which they divided into four parts, each part consisting of three hours this was a matter well known, and Christ puts the question as such, it being what might be easily answered, and at once assented to:
if any man walk in the day: within any of the twelve hours, even in the last of them,
he stumbleth not, at any stone or stumbling block in the way,
because he seeth the light of this world; the sun in the horizon not being as yet set, by the light of which he sees what is before him, and avoids it; See Gill on John 8:12. So our Lord intimates, that as yet it was day with him, his time of life was not expired; and so, as yet, it was a time of walking and working; nor did he fear any danger he was exposed to, or any snares that were laid for him, since he could not be hurt by any, nor his life taken from him before his time.
(a) T. Bab Sanhedrin, fol. 88. 2. Avoda Zara, fol. 3. 2. Vid. Philo. de Somniis, p. 1143.

Jesus answered, Are there not twelve hours in the day?--(See on John 9:4). Our Lord's day had now reached its eleventh hour, and having till now "walked in the day," He would not mistime the remaining and more critical part of His work, which would be as fatal, He says, as omitting it altogether; for "if a man (so He speaks, putting Himself under the same great law of duty as all other men--if a man) walk in the night, he stumbleth, because there is no light in him."

Are there not twelve hours in the day? This is his answer to the protest of his disciples against going to Judea again, where the Jews seek his death. He sees his course clearly and is walking in the day.

Are there not twelve hours in the day? - The Jews always divided the space from sunrise to sunset, were the days longer or shorter, into twelve parts: so that the hours of their day were all the year the same in number, though much shorter in winter than in summer. If any man walk in the day he stumbleth not - As if he had said, So there is such a space, a determined time, which God has allotted me. During that time I stumble not, amidst all the snares that are laid for me. Because he seeth the light of this world - And so I see the light of God surrounding me.