Didymus the Blind (ca. 313 – ca.398) was an ecclesiastical writer of Alexandria whose famous catechetical school he led for about half a century, during the papacy of St. Athanasius.  Although he became blind at the age of four, before he had learned to read, he succeeded in mastering the whole gamut of the sciences then known. Upon entering the service of the Church he was placed at the head of the Catechetical School of Alexandria, where he lived and worked. 

He was a loyal student of Origen, and stoutly opposed to Arian and Macedonian teachings. Such of his writings as survive show a remarkable knowledge of scripture, and have distinct value as theological literature. Jerome, who often spoke of Didymus not as the blind but as "the Seer," wrote that Didymus "surpassed all of his day in knowledge of the Scriptures" and Socrates of Constantinople later called him "the great bulwark of the true faith." Didymus was viewed as an orthodox Christian teacher and was greatly respected and admired up until at least 553 when the Second Council of Constantinople (not recognized by our Coptic church) condemned his works but not his person. As a result of his condemnation many of his works were not copied during the Middle Ages and were subsequently lost. However, a group of 6th or 7th century papyrus codices discovered in 1941 near Toura, Egypt (south of Cairo) include his commentaries on Job, Zechariah, and Genesis.
    Despite his blindness, Didymus excelled in scholarship because of his incredible memory. He found ways to help blind people to read, and experimented with carved wooden letters, a precursor to Braille systems used by the blind today. Among his disciples were Saint Gregory of Nazianzen, Saint Jerome, Rufinus and Palladius. Saint Anthony once said to Saint Didymus: "Do not be sad that you have no eyesight  which the animals, and even the insects, share, but remember that you have divine insight with which you can see the light of divinity". Here is a sample of his writings:

The Lord said to the devil, The Lord rebuke you, devil, and the Lord who has chosen Jerusalem rebuke you. Lo, is not this man like a brand snatched from the fire? (Zech 3:2) ... There is need to understand how the Lord speaks to the devil .... It is not by use of any overt language in one of the human idioms that the Lord of all communicates to the devil, nor does he employ vocal organs, incorporeal and spiritual being as he is. Nor does the devil to whom the words were addressed have a sense of hearing affected by sounds composed of syllables, especially when it is God who is speaking. Reading the book of Job, for example, and finding there God speaking to the devil and the devil to God, (Job 1:7-12, 2-6) we are not so naive as to think that questions and answers were delivered overtly in human discourse, a different mode being suited and appropriate to the persons in question. In other words, God speaks by indicating what he wishes to those he decides will hear him, as likewise he hears those conversing with him by knowing what they have in mind. 

Joshua was dressed in filthy clothes and standing before the angel, who said in addressing those standing before him, Take the filthy clothes off him..  He said to him, See, 1 have taken away your iniquities. Put on him a long tunic, and place a clean turban on his head. They clothed  him in garments. (Zech 3:3-5) ... Jesus the great high priest, of whom Joshua represents a type in figurative mode, living in Babylon as he did along with the captives, put on as filthy clothes the sins of all human beings without sinning himself or experiencing sin. To put off and remove the weave of sin that he put on for our sake, he mounted the cross, so that the theologian Peter, Christ's apostle, writes, "He who bore our sins in his body on the cross so that, rid of sin, we might live by his righteousness." (1Pe 2:22,24)

>From the book: DIDEMUS THE BLIND: COMMENTARY ON ZECHARIAH, pp 68-69,72. available from: amazon .com

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