"Do his commandments" or "wash their robes" in Revelation 22:14?

"Blessed are they that do his commandments, that they may have right to the tree of life, and may enter in through the gates into the city." (Revelation 22:14, KJV)

Most modern versions, having followed the NA/UBS Greek text, replace "do his commandments" with "wash their robes". This NA/UBS reading is from the Greek manuscripts Aleph, Alexandrinus, 1006, 1841, 2050, 2053, 2062, and the Church fathers, Pseudo-Athanasius, Ambrose, Fulgentius, and Apringius. The KJV reading, following the Textus Receptus, is supported by the majority of Byzantine manuscripts, including 205, 209, 1611^supp, 1854, 2030, 2329, 2377, and uncial 046. It is also cited by the Church fathers, Andrew, Tertullian, Cyprian, Caesarius and Beatus. For example, Cyprian from 250AD says, "Item illic : Ego sum a et o, primus et novissimus, initium et finis. Felices eos qui faciunt praecepta ejus, ut sit potestas eorum super lignum vitae" (Testimoniorum Libri Tres Adversus Judaeos, Liber II, Cap. XXII). The KJV reading, being supported by 046 from the 10th century, is predated by only two manuscripts which support the NA/UBS reading. The KJV reading therefore is backed by strong external evidence.

This textual variant most likely arose from a careless scribe as the two variants share most of the same letters. Compare the following (same letters are underlined):

"οι ποιουντες τας εντολας αυτου" (Textus Receptus)
"οἱ πλύνοντες τὰς στολὰς αὐτῶν" (NA/UBS)

Although "οἱ πλύνοντες τὰς στολὰς αὐτῶν" is in earlier extant copies, these early manuscripts are demonstrably full of careless transcription. Sinaiticus has "ιρις" for "θριξ" (Revelation 10:1), "πρωτα" for "προβατα" (Revelation 21:4), and "καινα" for "κενα" (Revelation 21:5), making for some awkward readings that are unanimously rejected. Knowing that early manuscripts had such errors, it is certainly reasonable to suppose that an early scribe mistook "οι ποιουντες τας εντολας αυτου" for "οἱ πλύνοντες τὰς στολὰς αὐτῶν."

The Textus Receptus reading makes more sense. The word "wash" in the NA/UBS reading is a present participle in the Greek, signifying an ongoing action. Hence the washing of robes is expressed to be an ongoing action, not a single occurrence. However, this notion of ongoing washing is at odds with what the Bible says elsewhere about being washed. Revelation 7:14 says that those who came out of great tribulation "washed their robes, and made them white in the blood of the Lamb." "Washed" is in the aorist tense which does not necessarily suggest ongoing action. This makes sense because, as is revealed by this verse, the washing of robes symbolizes the cleansing by the blood of Christ. Such an act is a completed event at the time of conversion. Revelation 1:5 says that Christ "washed us from our sins in his own blood". To "do his commandments", however, is an ongoing act even in other passages of scripture ("keep his commandments": 1 John 2:3, 3:22, 5:2-3, Revelation 12:17, 14:12). Revelation 22:14 switches "keep" to "do" because the immediate context contrasts the "doing" of immoral conduct with the "doing" of godly conduct (Revelation 22:11-15). With respect to the criticism that the Textus Receptus reading supports a work-based salvation, the reading does not support a work-based salvation any more than other passages of John in the Gospel and the Epistle which call upon true Christians to keep Christ's commandments. Consider 1 John 3:23-24: "And this is his commandment, That we should believe on the name of his Son Jesus Christ, and love one another, as he gave us commandment. And he that keepeth his commandments dwelleth in him, and he in him. And hereby we know that he abideth in us, by the Spirit which he hath given us."