´It was narrated from 'Abdullah bin Rubayyi'ah that he was with the Messenger of Allah (S.A.W) on a journey and he heard the voice of a man calling the Adhan, and he said what he said. Then he said:` "This is a shepherd or a man who is away from his family." So they looked and so it was a shepherd.
Explanation & Benefits
Hafiz Muhammad Ameen
666. Commentary: In the desert, where the call to prayer (adhan) cannot be heard, if a lone traveler or shepherd wishes to perform the prayer, he should give the adhan. However, if the adhan from a nearby settlement can be heard, then that suffices and a separate adhan is not necessary. Also see: [حديث : 645]
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 666