Sunan Abi Dawud 2611
سنن أبي داود#2611Da'ifNarrated Abdullah ibn Abbas: The Prophet (ﷺ) said: The best number of companions is four, the best number in expeditions four hundred, and the best number in armies four thousand; and twelve thousand will not be overcome through smallness of numbers. Abu Dawud said: What is correct is that this tradition is mursal (i.e. the link of the Companion is missing)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautDaif
Zubair Ali ZaiDaif
In-book reference: 15:135