Matthew 21:12-13, Mark 11:15-17, Luke 20:45-46.
Jesus found many people were buying and selling when he entered the temple. He drove them all out, and knocked over the table of moneychangers and seats of dove sellers. and said "This is written in the scriptures, 'My house will be called a house of prayer', but you are making it a den of thieves".
Jesus did the same thing previously (John 2:14), it seems temples are very good place for merchants to do their job because many people are coming. The Scripture Jesus quoted is Isaiah 56:7.
