Whereunto shall we liken the kingdom of God? or with what comparison shall we compare it! In the first clause of this verse the best authorities give πῶς for τίνι, How shall we liken the kingdom of God? and in the second clause, instead of the Greek of which the Authorized Version is the rendering, the best-approved reading is ( τίνι αὐτὴν παραβολῇ θῶμεν), in what parable shall we set it forth? Our Lord thus stimulates the intellect of his hearers, by making them his associates, as it were, in the search for appropriate similitudes (see Dr. Morison, in loc.). The kingdom of God, that is, his Church on earth, is like a grain of mustard seed. By this image our Lord shows the great power, fertility, and extension of the Church; inasmuch as it started from a very small and apparently insignificant beginning, and spread itself over the whole world. It is not literally and absolutely true that the grain of mustard seed is less than all seeds. There are other seeds which are less than it. But the expression may readily be allowed when we compare the smallness of the seed with the greatness of the results produced by it. It is one of the least of all seeds. And so the preaching of the Gospel and the establishment of the Church was one of the smallest of beginnings. Perhaps the well-known pungency of the seed of the mustard plant may suggest the quickening, stimulating power of the Gospel when it takes root in the heart. The mustard plant shoots out large branches, which are used as fuel in some countries, quite large enough for shadow for the birds. A traveler in South America says that it grows to so large a tree upon the slopes of the mountains of Chili that he could ride under its branches.
With many such parables; such, that is, as he had just been delivering—plain and simple illustrations which all might understand; not abstruse and difficult similitudes, but sufficiently plain for them to perceive that there was heavenly and Divine truth lying hidden beneath them, so that they might be drawn onwards through that which they did understand, to search into something hidden beneath it, which at present they did not know. But privately to his own disciples he expounded ( ἐπέλυε) all things. This word ( ἐπιλύω) occurs nowhere else in the Gospels. But it does occur in St. Peter's second Epistle (2 Peter 1:20), "No Scripture is of any private ( ἐπιλύσεως) exposition, or interpretation." This suggests a connection between St. Mark's Gospel and that Epistle, and may be accepted as an auxiliary evidence, however small, as to the genuineness of the Epistle.
And on that day,—the day, that is, on which the parables were delivered, at least those recorded by St. Mark—when even was come, he saith unto them, Let us go over unto the other side. And leaving the multitude, they take him with them, even as he was, in the boat. It was the boat from which he had been preaching. They made no special preparation. They did not land first to obtain provisions. It would have been inconvenient to go ashore in the midst of the crowd. They made at once, as he told them to do, for the other side. And other boats were with him. This is another interesting circumstance. Probably those who were in these boats had availed themselves of them to get nearer to the great Prophet, the boatmen themselves having seen the vast crowd that was gathered on the shore, and so having been attracted thither. Thus he had a large audience on the sea as well as on the land. And not it was so ordered that he was surrounded by a fleet and by a multitude of witnesses when he stilled the tempest.