Mass. Gen. Laws ch. 140, § 109: Receipt; part payment

Section 109. If a payment is made on account of a loan to which sections ninety-six to one hundred and eleven, inclusive, apply, the person who receives the payment, or his principal, shall, when the payment is taken, give to the person paying a receipt setting forth the amount then paid and the amount previously paid, and identifying the loan, note, mortgage or assignment to which it is to be applied.