Massachusetts Constitution Pt. 2, Ch. II, § 1, Art. 13

ART. XIII. As the public good requires that the governor should not be under the undue influence of any of the members of the general court by a dependence on them for his support, that he should in all cases, act with freedom for the benefit of the public, that he should not have his attention necessarily diverted from that object to his private concerns--and that he should maintain the dignity of the commonwealth in the character of its chief magistrate, it is necessary that he should have an honorable stated salary, of a fixed and permanent value, amply sufficient for those purposes, and established by standing laws: and it shall be among the first acts of the general court, after the commencement of this constitution, to establish such salary by law accordingly.

Permanent and honorable salaries shall also be established by law for the justices of the supreme judicial court.

And if it shall be found that any of the salaries aforesaid, so established, are insufficient, they shall, from time to time be enlarged as the general court shall judge proper.