Mich. Comp. Laws § 767.9
The clerk of the court shall prepare an alphabetical list of all the persons returned as grand jurors. When the jury is to be impaneled, the following oath shall be administered to the jurors: "You as grand jurors of this inquest do solemnly swear that you will diligently inquire and true presentment make of all such matters and things as shall be given you in charge; your own counsel and the counsel of the people, and of your fellows, you shall keep secret; you shall present no person for envy, hatred or malice, neither shall you leave any person unpresented for love, fear, favor, affection or hope of reward; but you shall present things truly, as they come to your knowledge, according to the best of your understanding; so help you God".
MCL 767.9