Narrated from Abi Sukainah One of the Companions: The Prophet ﷺ said: Let the Abyssinians alone as long as they let you alone, and let the Turks alone as long as they leave you alone.
Hadith Referenceسنن ابي داود / كتاب الملاحم / 4302
1؎: This was a military strategy that the Prophet sallallahu alayhi wa sallam taught the Muslims: that as long as these disbelieving nations do not take action against the Muslims, the Muslims too should not initiate fighting against them.
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues: If the unity of the Muslims is not established, then this same ruling applies; acting upon (قاتِلُوا المشرکین کافَّةً) [“Fight against the polytheists collectively”] is obligatory, and in the best of generations, this very practice was implemented. And Allah knows best.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 4302