..please safeguard him from going abroad with the field army

[Robert Vermaat]

Mios treats Abinnaeus as an equal, and he is one of the two only authors to address Abinnaeus as "beloved brother", a Christian type of greeting.

Christian, sure, but also personal, if the two were related. It just occurred to me that the writer might be related to the commander himself - that would give an even better reason to write such a request. he's not asking a favour for the relative of his wife to someone who knows his wife. More likely, he the link himself, they know each other, and he's asking the commander for a favour on behalf of their relation.

'Beloved brother' could therefore be to a 'brother in the Lord', but also to his own brother.. Or maybe they were friends.