Jump To ECM Entry Online Commentary Introduction
GC: Reading a has many close A-related witnesses, but there is a strong tendency for b to a in the TFD.
TP: καθῶς γέγραπται is by far more common than ὡς γέγραπται where OT citations are introduced in the NT (27 out of 29 cases in NA28, with Mark 7:6 and Luke 3:4 as counterexamples). Hence b may be seen as an atypical MT reading.
There is a coherent attestation for an atypical majority reading, but the difference between καθῶς and ὡς appears too slight to justify a decision for b on this basis. Moreover, ὡς may be an Atticism.[1] The patristic evidence is split: Irenaeus is the oldest witness for ὡς while Origen cites both variants.
[1] Kilpatrick, “Mark i 45,” 160, notes that “Phrynichus condemns καθώς.”