The origin of the Arabic word barid (“the post”) is problematic; various interpretations have been advanced, but are based solely on linguistic reasoning, which is an essential yet insufficient approach. Loan words like barid must be assessed in the global historic and anthropological context of the Middle East during the transition to Islam. In particular, the importance of oral culture during this period in Sasanian and Arab societies needs to be considered.
BosworthC. E., '“Barīd”', in EIr., (London/New-York1988) 797-798fasc. 8onlinehttp://www.iranicaonline.org/articles/barid-the-official-postal-and-intelligence-service-of-the-early-islamic-caliphate-and-its-successor-states.