How did the petition of right protect a person who is arrested

The Petition of Right, initiated by Sir Edward Coke, was based upon earlier statutes and charters and asserted four principles: no taxes may be levied without consent of Parliament; no subject may be imprisoned without cause shown (reaffirmation of the right of habeas corpus); no soldiers may be quartered upon the citizenry; martial law may not be used in time of peace.

The Petition of Right was made to prevent the king from arresting whoever he wanted. For the king to arrest someone he needed a cause.