The Commissioner of State Lands shall take an oath that he or she will not, directly or indirectly, be engaged in the purchase of lands belonging to the state, to be sold by him or her during his or her continuance in office, and that he or she will not, directly or indirectly, engage in any speculation in swamp and overflowed lands or give information to any agent, friend, or secret or other partner, so as to secure the advantages of such information to himself or herself to any person, association, or company, to the prejudice or exclusion of other persons.