The wordplay depends upon the Greek, “you are Petros and upon this petra (rock) I will build my church” and lends itself more easily to thinking of Peter as foundation for the emerging community than the Aramaic kephā’, which usually designates a stone. Reconstructing the tradition behind Matthew 16:17–19 is controversial. For a conservative view, see W.D. Davies and Dale C. Allison, A Critical and Exegetical Commentary on the Gospel According to Matthew, vol. 2:8-18 (Edinburgh: T & T Clark, 1991), pp. 621–639. However, ekklēsia (“church”) does not go back to the tradition of Jesus’ sayings. Matthew 16:18 probably attaches this explanation of Simon’s name change to the apostle’s role in establishing the community after Easter (see John Meier, A Marginal Jew, vol. 3, Companions and Competitors [New York: Doubleday, 2001], pp. 224–234).