The Messenger of Allah ﷺ said to Aktham bin Jawn al-Khuzai, "Aktham, go on military expeditions with people other than your own clan, for it will improve your character and make you honored among your companions. Aktham, the best of companions are four, the best of raiding parties are four hundred, the best of armies are four thousand, and twelve thousand will never be defeated due to small numbers."
حدثنا هشام بن عمار حدثنا عبد الملك محمد الصنعاني حدثنا أبو سلمة العاملي عن ابن شهاب
أن رسول الله ﷺ قال لأكثم بن الجون الخزاعي يا أكثم اغز مع غير قومك يحسن خلقك وتكرم على رفقائك يا أكثم خير الرفقاء أربعة وخير السرايا أربع مائة وخير الجيوش أربعة آلاف ولن يغلب اثنا عشر ألفا من قلة
[Its chain of transmission is extremely daif] Ibn Abu Hatim mentioned it in Ilal al-Hadith, no. 2398, from the hadith of Abdul-Malik, with the chain suspended going back to him. Abu Hatim said that Abu Salama al-Aamili was discarded in hadith and used to lie, and that the hadith is baseless. Busiri likewise declared it daif because of the weakness of Abu Salama al-Aamili al-Azdi, who is discarded, and whom Abu Hatim accused of lying (Taqrib), and because Abdul-Malik bin Muhammad al-Sanani is weak in hadith (Taqrib). It has another route in Bayhaqi, 9/... and so on, narrated at 157, but its chain is thoroughly daif.As for the final part, "The best of the companions are four," it is narrated by Abu Dawud, no. 2611. Tirmidhi graded it hasan, and Ibn Khuzayma graded it sahih, no. 2538, as did Ibn Hibban, no. 663, along with Hakim, 443/1, 2/101, and Dhahabi. But its chain is daif because of Zuhri's ambiguous transmission using "an," as noted earlier, no. 707, and it contains other defects as well.