The promise looks forward to an entirely altered state of things spoken of as "the regeneration"--a remarkable term, reminding us of the vast scope of our Saviour's mission as ever present to His consciousness even in these days of smallest things. The word recalls what is said in the book of Genesis as to "the generation of the heaven and of the earth," and suggests by anticipation the words of the Apocalypse concerning the regeneration, "Behold, I make all things new," and "I saw a new heaven and a new earth." That the reference is to that final restitution of all things, and not merely to the new dispensation, seems evident from the words which immediately follow: "When the Son of man shall sit on the throne of His glory." Why, then, was the promise given in words so suggestive of those crude notions of an earthly kingdom, above which it was so difficult and so important for the disciples to rise? The answer is to be found in the limitation of human language: "Eye hath not seen, nor ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love Him"; accordingly, if the promise was to be of any use to them in the way of comfort and encouragement, it must be expressed in terms which were familiar to them then. To their minds the kingdom was as yet bound up with Israel; "the twelve tribes of Israel" was as large a conception of it as their thoughts could then grasp; and it would certainly be no disappointment to them when they afterwards discovered that their relation as apostles of the Lord was to a much larger "Israel," embracing every kindred and nation and people and tribe; and though their idea of the thrones on which they would sit was then and for some time afterwards quite inadequate, it was only by starting with what ideas of regal power they had, that they could rise to those spiritual conceptions which, as they matured in spiritual understanding, took full possession of their minds.
The Lord is speaking, however, not for the apostles alone, but for all His disciples to the end of time; so He must give a word of cheer, in which even the weakest and most obscure shall have a part (ver. 29). Observe that here also the promise is only for those who have left what they had for the sake of Christ. We are not authorised to go with a message after this form: "If you leave, you will get." The reward is of such a nature that it cannot be seen until the sacrifice is made. "Except a man be born again, he cannot see the kingdom of God;" until a man loses his life for Christ's sake, he cannot find it. But when the sacrifice has been made, then appears the compensation, and it is seen that even these strong words are not too strong: "Every one that hath forsaken houses, or brethren, or sisters, or father, or mother, or wife, or children, or lands, for My name's sake, shall receive an hundredfold, and shall inherit everlasting life." The full consideration of this promise belongs rather to St. Mark's Gospel, in which it is presented without abridgment.
The supplementary caution--"But many that are first shall be last; and the last shall be first"--is administered in apparent reference to the spirit of the apostle's question, which exhibits still some trace of mercenary motive, with something also of a disposition to self-congratulation. This general statement is illustrated by the parable immediately following it, a connection which the unfortunate division into chapters here obscures; and not only is an important saying of our Lord deprived in this way of its illustration, but the parable is deprived of its key, the result of which has been that many have been led astray in its interpretation. We cannot attempt to enter fully into the parable, but shall only make such reference to it as is necessary to bring out its appropriateness for the purpose our Lord had in view. Its main purport may be stated thus: many that are first in amount of work shall be last in point of reward; and many that are last in amount of work shall be first in point of reward. The principle on which this is based is plain enough: that in estimating the reward it is not the quantity of work done or the amount of sacrifice made that is the measure of value, but the spirit in which the work is done or the sacrifice made. The labourers who made no bargain at all, but went to work on the faith of their Master's honour and liberality, were the best off in the end. Those who made a bargain received, indeed, all they bargained for; but the others were rewarded on a far more liberal scale, they obtaining much more than they had any reason to expect. Thus we are taught that those will be first who think least of wages as wages, and are the least disposed to put such a question as, "What shall we then have?" This was the main lesson for the apostles, as it is for all who occupy places of prominence in the kingdom. It is thus put in later years by one of those who now for the first time learned it: "Look to yourselves, that we lose not those things which we have wrought, but that we receive a full reward" (2 John 8). "Look to yourselves," see that your spirit be right, that there be nothing selfish, nothing mercenary, nothing vainglorious; else much good labour and real self-denial may miss its compensation.