In the preceding passage, John had been questioned and had given testimony to Christ. Now he gives further testimony spontaneously, giving the testimony first and then confirming what he had said before, in the words: ‘And John gave testimony saying … ‘ The circumstances of his giving testimony are described in the first place, followed by his exact words: ‘Behold the Lamb of God'; his witness is excluded from suspicion by the words: ‘And I knew him not'.

Details of the circumstances are given firstly as to time, where it says, ‘The next day', and here the perseverance of St John is especially commended, because he went on giving testimony to our Lord, not upon one day alone, nor even once only, but upon several days and at different times: ‘Every day will I bless thee'. (Ps. 144.) His increase in fervour is also commended, for we ought not to allow each succeeding day to pass without variation; it ought to be different from the preceding, which means better, as the Psalmist says: ‘They shall go from virtue to virtue.’