The following oath shall be administered to all of the members of the grand jury:
"Do you as a member of this grand jury of the State of New Jersey and county of (county) swear or affirm that you will support the Constitution of the United States and the Constitution of this State; that you will diligently inquire into all matters brought before you to the best of your skill, knowledge and understanding; that you will take no action through envy, hatred or malice nor for fear, favor or affection, or for reward or the hope of reward; that you will make a true presentment of all matters coming before you, and that you will keep secret the proceedings of the grand jury?"