Dr. Richard B. Gaffin, Jr. speaks about Calvin's views on the Sabbath. In this conversation, we look to Dr. Gaffin's book Calvin and the Sabbath: The Controversy of Applying the Fourth Commandment (Mentor/Christian Focus), which is a revised version of his ThM thesis originally written under the supervision of John Murray at Westminster in 1961–62. We also speak about Dr. Gaffin's exegesis and theological development of Hebrews 3–4 in Pressing Toward the Mark: Essays Commemorating Fifty Years of the Orthodox Presbyterian Church.