‘But when it was now the middle of the Feast, Jesus went up into the Temple and taught.'
The Temple was the place where religious teachers would regularly go to pass on their teachings. They would sit to teach, and their disciples would gather round them while they sat and taught, whilst interested onlookers were welcome to listen and to ask questions (compare Luke 2:46).
So Jesus waited until half way through the week, and then Himself went up to the Temple to teach. Although He was aware of the constant threat against Him He knew that He must do the Father's will and fulfil His destiny. It was an act that brought out His great courage.