Thomas Boston, Works, 1:341:
O heavy, yet happy exchange! heavy for Christ the Surety, but happy for poor sinners. Here is what is got on either hand by the exchange of the persons of Christ and his redeemed ones. All the sins of the redeemed are charged on Christ for the satisfaction of justice by suffering for them: and all Christ’s righteousness, for life and salvation, is reckoned on their score, 2 Cor. 5:21. The curse of the law comes on him for their sake: and the blessing of the gospel comes on them for his sake, Gal. 3:13, 14.
O heavy, yet happy exchange! heavy for Christ the Surety, but happy for poor sinners. Here is what is got on either hand by the exchange of the persons of Christ and his redeemed ones. All the sins of the redeemed are charged on Christ for the satisfaction of justice by suffering for them: and all Christ’s righteousness, for life and salvation, is reckoned on their score, 2 Cor. 5:21. The curse of the law comes on him for their sake: and the blessing of the gospel comes on them for his sake, Gal. 3:13, 14.