John 5:14

Afterward Jesus findeth him in the temple
Perhaps on the same day; for as soon as he had been at home, and laid down his bed, it is very likely he went directly to the temple, there to show himself, attend the worship of the place, and return thanks to God for the great mercy bestowed on him:

and said unto him, behold thou art made whole;
cured of the disease that had attended him so many years; and a wonderful cure it was; well may a "behold" be prefixed; though this is here not only a note of admiration, but of attention, to what he was about to say to him: sin is a disease, which is original, natural, and hereditary to men; it is an epidemical one, all are affected with it, and all the powers and faculties of the soul; and it is a nauseous and loathsome one; and what is mortal and incurable in itself, and only to be cured by the great physician, Jesus Christ: God's elect are attended with it as others, and being made sensible thereof, they come to Christ for a cure, and receive one, as this man did, to whom he said,

sin no more;
intimating, that as all diseases of the body spring from sin, so had his; and that the time past of his life should suffice, for a course of sinning; and that the mercy he had received, laid him under an obligation to guard against it, to which there would still be a proneness in him; nor did our Lord imagine, that he could hereafter live without sin, but that he should not indulge himself in it, and give up himself unto it, and live in it: so all the diseases of the soul arise from sin; and when a person is converted, he ought not to walk as others do, or he himself has done; and though there is a propensity to sin and backslide from God after conversion, yet the grace of God teaches men to deny sin, and to live righteously; and though it cannot be thought that they should be, and act without sin, yet it becomes them not to live in sin, or go on in a course of it, as heretofore:

lest a worse thing come unto thee;
for God could send a worse disease, or a sorer affliction, than he had yet done; an heavier punishment, either in this world, or that to come: and apply this to a good man, a converted man, one called by grace and cured by Christ, and a worse thing through sin may come unto him than a bodily disorder, namely, the hidings of God's face; for as his presence is life, his absence is death, to such persons; and as for such who only make a profession of religion, and are externally reformed only, such, if they sin and fall away, their latter end is worse than the beginning.