This study explores a cluster of six letters preserved in the Cairo Geniza written by a Jewish father from Alexandria in the first half of the thirteenth century. The writer’s son ran away from home, abandoned the family shop and overall behaved in a way unbecoming for a young middle-class Jewish man. This study uses this little-studied cluster of documents to examine the ties that bound a young Jewish man to his family and community, including exchange of letters, economic considerations, familial bonds and religious expectations. The father’s letters offer a case study for approaching social ties and cultural expectations as dynamic and ongoing work performed by specific agents. The letters are useful for recovering an urban middle-class conception of masculinity prevalent in the medieval Islamic world that emphasized belonging to social networks and required men to uphold their responsibilities to those dependent upon them.