In my question, I stated that I was far from convinced that the omission of the article is enough to believe that Mark 1:9 is an interpolation. After some months, I noticed other features of Mark 1:9 that now support a reading of this verse as having been redacted.
Mark 1:9 is the only place in the entire Gospel where the town of Nazareth is mentioned, in the original Greek language. Moreover, the reference to “Nazareth of Galilee” is unusual for Mark – elsewhere, he refers to towns and cities such as Capernaum,Tyre, Sidon, Dalmanutha, Bethphage, Bethany and Jerusalem without telling us where these towns are.
Although English translations of Mark's Gospel often refer to 'Jesus of Nazareth' (eg Mark 1:24), the Greek text says in each instance, Ἰησοῦ Ναζαρηνέ (Jesus the Nazarene). While verse 1:9 only says that Jesus departed from Nazareth to meet John the Baptist, this is the nearest Mark ever gets to locating Jesus in Nazareth.
An argument against Nazareth as Jesus’ home town is that there is another town that, for Mark, might have been his home town. Apart from Nazareth in verse 1:9, the first town that Mark mentions is Capernaum, and some modern Bibles translate Mark 2:1,15; 3:20 in a way that suggests Capernaum was really the home town of Jesus:
Mark 2:1 (NAB): When Jesus returned to Capernaum after some days, it became known that he was at home.
Mark 2:15 (NAB): While he was at table in his house …
Mark 3:20: (NAB): He came home ...
The later gospels leave no doubt that Jesus was from Nazareth. However, Matthew supports the above translations of Mark 2:1, 15; 3:20 because it tells us in verse 4:13 that Jesus moved there from Nazareth. With a slightly different approach, Luke 5:29 says that the house of Mark 2:15 is Levi’s house.
Mark 1:9 has three features, unusual for Mark, that, seen in combination, lead to a reasonable conclusion that the verse has been redacted:
- Omission of the definite article before the name of Jesus;
- Only mention of Nazareth in the entire Gospel;
- Nazareth is mentioned as being in Galilee.
To reach this conclusion, it is not necessary to explain why the verse was altered, but I believe this was done in order to place Jesus in Nazareth at the beginning of his mission on earth and therefore harmonise with the later gospels that tell us that Jesus was actually brought up in Nazareth. Knowing that Jesus began his mission from Nazareth, the reader would conclude that 'Jesus the Nazarene' had the same meaning in Mark as 'Jesus of Nazarene' had in the later gospels.