tc Most mss (A C3 Ψ 33 𝔐) have τὸ εἰ δύνασαι πιστεῦσαι (to ei dunasai pisteusai, “if you are able to believe”), instead of τὸ εἰ δύνῃ (to ei dunē, “if you are able”; supported by א B C* L N* Δ f1 579 892 pc). Others have εἰ δύνῃ (or δυνάσαι) πιστεῦσαι (“if you are able to believe”; so D K Θ f13 28 565 al), while still others have τοῦτο εἰ δύνῃ (touto ei dunē, “if you can [do] this”; so [𝔓45] W). The reading that best explains the rise of the others is τὸ εἰ δύνῃ. The neuter article indicates that the Lord is now quoting the boy’s father who, in v. 22, says εἴ τι δύνῃ (ei ti dunē, “if you are able to do anything”). The article is thus used anaphorically (see ExSyn 238). However, scribes could easily have overlooked this idiom and would consequently read τὸ εἰ δύνῃ as the protasis of a conditional clause of the Lord’s statement. As such, it would almost demand the infinitive πιστεῦσαι, producing the reading τὸ εἰ δύνασαι πιστεῦσαι (“if you are able to believe, all things are possible …”). But the article here seems to be meaningless, prompting other scribes to modify the text still further. Some dropped the nonsensical article, while others turned it into the demonstrative τοῦτο and dropped the infinitive. It is clear that scribes had difficulty with the original wording here, and made adjustments in various directions. What might not be so clear is the exact genealogy of the descent of all the readings. However, τὸ εἰ δύνῃ is both a hard saying, best explains the rise of the other readings, and is supported by the best witnesses. It thus rightly deserves to be considered authentic.