John 5:5 - Ellicott's Commentary On The Whole Bible

Thirty and eight years. — The period expresses, not his age on the one hand, nor the time of his being at Bethesda on the other, but the time during which he had suffered from the infirmity. Helpless and friendless, having spent half the lot of human life in that condition, he appeals without an uttered word to the Mercy which is present in the House of Mercy; and to him alone of those He healed does Christ of His own accord address the first question. The infirmity was in some way connected with youthful sin (John 5:14), and the sufferer and his history would be well known to those at Jerusalem. The exact knowledge of the writer tells us that for thirty-eight years he had paid sin’s. penalty.