Matt 5:48 ωσπερ

There are several reasons why ωσπερ, supported by most manuscripts (including D E K M S U W Δ Θ Π 346 565 579 1006 1342), came to be altered to the shorter ως (ℵ B L Z Σ f1.13 33 892 1241; Cl Or). First, it seemed too difficult to some that man should be "just like" or equal to (ωσπερ) God's perfection rather than simply "as" or similar to (ως) it. Second, the far less common ωσπερ (42x in the NT) is much more likely to have yielded to the more common ως (500x in the NT), than vice versa. Third, parablepsis error could have aided the omission of -περ, either (a) from the -π- of ωσπερ to the π- of πατηρ or (b) from the similarity of -ΠΕΡ to the nomen sacrum for father, ΠΗΡ. Furthermore, the alteration of ωσπερ to ως is not unique here, but also occurs elsewhere in a minority of manuscripts or fathers:

Matt 6:5 (ℵ B D Z 33 pc)
Matt 6:16 (ℵ B D Δ f1 892 pc)
Matt 12:40 (Or)
Matt 24:38 (ℵ B L 33 892*)
Luke 18:11 (D L Q Ψ 892 1241 pc)
John 5:21 (ℵ)
John 5:26 (ℵ* D W; Epiph)
Acts 11:15 (D)
1 Cor 10:7 (C D* K P pc)
2 Cor 1:7 (ℵ A B C D* E M P 33 pc)
Eph 5:24 (ℵ A D* F G P 33 pc; omit: B Ψ pc b)

Cf. also the notes on Matt 6:5 ωσπερ, Matt 6:16 ωσπερ, and Matt 24:38 ωσπερ.