John Lightfoot on John 5:1

[After this there was a feast of the Jews.] The other evangelists speak but sparingly of Christ's acts in Judea; this of ours something more copiously. They mention nothing of the Passovers from his baptism to his death, excepting the very last; but St. John points at them all. The first he speaks of chapter 2:13; the third, chapter 6:4; the fourth, chapter 13:1; and the second, in this place. It is true he does not call it by the name of the Passover here, but only a feast in general. However, the words of our Saviour mentioned above, chapter 4:35, do give some kind of light into this matter.