Mass. Gen. Laws ch. 127, § 89: Maintenance of sabbath schools and schools for instruction

Section 89. The superintendent of any correctional institution of the commonwealth, with the consent of the commissioner, may cause a sabbath school to be maintained in the institution for the instruction of the inmates in their religious duties, and may permit such persons as he considers suitable to attend it as instructors, under such regulation as the commissioner may establish. The superintendent may also, except on Sunday, and subject to the approval of the commissioner, maintain schools of instruction for the prisoners.