Albert Barnes on John 5:9

The Sabbath. To carry burdens on the Sabbath was forbidden in the Old Testament, Jer 17:21, Neh 13:15, Ex 20:8-10. If it be asked, then, why Jesus commanded a man to do on the Sabbath what was understood to be a violation of the day, it may be answered,

1st. That the Son of man was Lord of the Sabbath, and had a right to declare what might be done, and even to dispense with a positive law of the Jews, Mt 12:8, Jn 5:17.

2nd. This was a poor man, and Jesus directed him to secure his property.

3rd. The Jews extended the obligation of the Sabbath beyond what was intended by the appointment. They observed it superstitiously, and Jesus took every opportunity to convince them of their error, and to restore the day to its proper observance, Mt 12:6-11, Lk 6:9; Lk 13:14, 14:5. This method he took to show them what the law of God really permitted on that day, and that works of necessity and mercy were lawful.

(h) "and on the same day" Jn 9:14