If so be ye have tasted that the Lord is gracious. If so be ye have tasted - Ειπερ εγευσασθε· Seeing ye have tasted. There could be no doubt that they had tasted the goodness of Christ who were born again, of incorruptible seed, and whose hearts were purified by the truth, and who had like precious faith with the apostles themselves.
That the Lord is gracious - Ὁτι χρηστος ὁ Κυριος· From the similarity of the letters, many MSS. and several of the fathers have read, Χριστος ὁ κυριος, the Lord is Christ, or Christ is the Lord.
This seems to refer to Psalms 34:8 : O taste and see that the Lord is good; Γευσασθε και ιδετε ὁτι χρηστος ὁ Κυριος, Sept. And there is still a reference to the sucking child that, having once tasted its mother's milk, ever after desires and longs for it. As they were born of God, and had tasted his goodness, they would naturally desire the same pure unadulterated milk of the word.