Didymus teaches that the essence of it is the doctrine of Christ, which binds souls and both mortifies and uplifts them to the extent that they can proclaim with Paul, “Who shall separate us from the love of Christ?” (Rom. 8:35).
And with the flow of Your sweetness, I shall drink. David echoes the thought expressed earlier, reaffirming it here. Just as he previously spoke of drinking, he now highlights the same. He asserts that You, O Lord, will intoxicate the believers with the stream of joy that emanates from You. The stream of sweetness represents the joyful teachings of Christ, which flowed forth from His mouth during His earthly ministry, proving to be powerful and dismantling those who opposed it, accompanied by the waves of the old law and the prophets. This river mirrors the winter torrent, being both temporary and forceful, merging with many waters. It is termed the stream of sweetness because the teachings of Christ spiritually uplift, as earlier indicated. Some, including Isychius, interpret the flow of the house as the pure blood that flowed from the side of the Word made flesh, while the stream signifies the water that accompanied the blood. Both have nourished us, the Gentile nations, and have filled us with such joy that we have emerged from the former idolatrous delusions.
According to Isychius, the stream of sweetness embodies the sufferings of Christ, a torrent arising amid the winter of our sins, during which all virtue, particularly love for God, lay dormant. This is why the prophet Zechariah speaks of the day of the Cross, stating: "In that day there shall be no light, cold and frost, neither day nor night, but at evening there shall be light" (Zech. 14:6, 7). It is aptly termed sweetness because Christ took great delight in enduring suffering for our sake. Some also refer to the Holy Spirit as the stream of sweetness.