Looking at the legal definition of a 'shaliach' - an agent or messenger, we get a couple of principles which seem to extend much further, to the idea of what it is to be human at all. 

 * You can find the sourcesheet with all the texts here: https://www.sefaria.org/sheets/336734?editor=1​

* A project of 58th Century Judaisms: https://www.58thcentury.world/