I. Into this world, where the fountains were all sin and uncleanness, Messiah came. And for a while He was a fountain sealed. Within His own bosom He carried the purity of heaven, the calm consciousness of His own divinity, a great deep of gentleness and love and compassion. But that was not enough. It was not enough that He should be a holy visitor, by His surpassing sanctity pronouncing a tacit verdict on the surrounding iniquity; an angelic tourist through the realms of earth, leaving them more wretched and lonely than before. He had come not so much a visitor as a victim, not so much to sojourn as to save. Found in fashion as a man, God the Son became the kinsman of sinners, and engaged in His own Person to achieve an ample atonement for the sins of the world. It was on Calvary that the fountain sealed of incarnate love became the fountain opened of redeeming merit.
II. The fountain is open still. Fresh and efficacious and free as on the day when His mighty sacrifice was offered, the merit of Immanuel still continues. The truth concerning Jesus, published in the Bible, is the fountain opened to the world. The man who believes that truth has his sins washed away. When the muddy Arve joins the limpid Rhone, after a while the bright waters grow troubled, and at last they flow together a turbid stream. But it is not so with this fountain. However many the sins, however much the defilement which it washes away, it springs pure and pellucid as ever, and the reason is that this fountain resembles the sea. Though a limited outlet, it is a boundless tide. In Persia, says a legend, there was a fountain, and if any impurity were cast into it there was sure to be a storm the selfsame day. But here is the very converse. Over the sinner's head are lowering the dark thunderclouds of wrath Divine; but, emboldened by God's own invitation, the sinner casts his sins into the fountain opened, and the sky is clear. God's anger is turned away, and with a pleasant countenance He beholds the believing and returning transgressor.
J. Hamilton, Works,vol. vi., p. 194.
References: Zechariah 13:1. Spurgeon, Sermons,vol. xvii., No. 971; B. Isaac, Thursday Penny Pulpit,vol. ix., p. 37; J. N. Norton, Golden Truths,p. 355.