Mass. Gen. Laws ch. 244, § 19: Tender of payment or performance

Section 19. The person entitled to redeem shall pay or tender to the mortgagee, or person claiming or holding under him, the whole amount then due and payable on the mortgage, and shall perform or tender performance of every other condition contained therein; and if there has been an action to recover the land he shall pay or tender the costs of such action if unpaid.