In this paper, we seek to show the ways in which Luther and Calvin interpret one of the most problematic texts in the Old Testament, Abraham's trial of sacrificing his beloved son Isaac. Both of them distance themselves from the traditional, allegorical approach to the passage. Instead, they pay careful attention to the episode itself and its relation to salvation history. God confronts Abraham with a contradiction. Our examination of the Reformers' treatments on the passage is arranged into five aspects, which are, the nature of the trial, the focus of the interpreter, the nature of faith, faith in the face of death, and the relationship between faith and work. Then it comes an analytical comparison of their respective treatment. Finally, we will apply their treatment of the passage as a case study in illustrating their hermeneutical principles of the Old Testament narrative.