From this verse it seems Jews picked a name among their relatives for their children. How exactly did this convention work?
Even today, Jews traditionally name children in honour of a relative.
Naming After Relatives
It is customary to name children after deceased parents.
- The Ashkenazic [northern European] custom is not to name a baby after living individuals.
- In Sephardic [south-west European] custom, naming children after living relatives (as well as deceased ones) is encouraged. This is considered an honor for the relative.
Luke 1:59 On the eighth day they came to circumcise the child, and they were going to name him after his father Zechariah, 60but his mother spoke up and said, “No! He is to be called John.”
61They said to her, “There is no one among your relatives who has that name.”
As pointed out by Ellicott, John is a name listed in Acts 4:6
Annas the high priest was there, and so were Caiaphas, John, Alexander and others of the high priest's family.
Zacharias was probably not related to the Sadducean high priests.
Barnes adds this note:
The Jewish tribes and families were kept distinct. To do this, and to avoid confusion in their genealogical tables, they probably gave only those names which were found among their ancestors. Another reason for this, common to all people, is the respect which is felt for honored parents and ancestors.