John 5:9b-13

The day on which this took place was a Sabbath, and so the Jewish leaders said to the man who had been healed, "It is the Sabbath, the law forbids you to carry your mat." But he replied, "The man who made me well said to me, 'Pick up your mat and walk.' " So they asked him, "Who is this fellow who told you to pick it up and walk?" The man who was healed had no idea who it was, for Jesus had slipped away into the crowd that was there. 

The day on which this took place was a Sabbath 
Mathew 12:9-13  Going on from that place, he went into their synagogue, and a man with a shriveled hand was there. Looking for a reason to bring charges against Jesus, they asked him, "Is it lawful to heal on the Sabbath?" He said to them, "If any of you has a sheep and it falls into a pit on the Sabbath, will you not take hold of it and lift it out? How much more valuable is a person than a sheep! Therefore it is lawful to do good on the Sabbath." Then he said to the man, "Stretch out your hand." So he stretched it out and it was completely restored, just as sound as the other.

so the Jewish leaders 
John 5:16  So, because Jesus was doing these things on the Sabbath, the Jewish leaders began to persecute him.

the law forbids you to carry your mat 
Nehemiah 13:17-18  I rebuked the nobles of Judah and said to them, "What is this wicked thing you are doing--desecrating the Sabbath day? Didn't your ancestors do the same things, so that our God brought all this calamity on us and on the city? Now you are stirring up more wrath against Israel by desecrating the Sabbath."
Jeremiah 17:21  " 'This is what the LORD says: Be careful not to carry a load on the Sabbath day or bring it through the gates of Jerusalem.' "
Matthew 12:2  When the Pharisees saw this, they said to him, "Look! Your disciples are doing what is unlawful on the Sabbath."

Scriptures taken from the Holy Bible, New International Version® NIV®, 
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