"a crown made of thorny branches" or "a crown made of branches with thorns on them"
# a staff in his right hand
They gave Jesus a stick to hold to represent a scepter that a king holds. They did this to mock Jesus.
# Hail, King of the Jews
They were saying this to mock Jesus. They were calling Jesus "King of the Jews," but they did not really believe he was a king. And yet what they were saying was true. (See: [[rc://en/ta/man/translate/figs-irony]])