Narrated 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).
1؎: That is, there should be at least four, because if one of them ever falls ill and wishes to make a bequest to one of his companions, then two of them will remain for testimony. In this hadith (if authentic), the minimum number is mentioned. The scholars have written: Five is better than four, and in fact, the more there are, the greater the good.
2؎: An army of twelve thousand will never be defeated due to its small number; so if other nations do prevail over it, the cause of that defeat will not be paucity, but rather the army falling into self-admiration and pride, or some other similar reason.
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues: ➊ The greater the number, ➋ the greater will be the blessing and benefit. ➌ If Muslims, numbering twelve thousand, are ever defeated somewhere, ➍ then the cause will not be their small number, but rather some other reason. ➎ For example, lack of piety (taqwa), ➏ arrogance, ➐ pride, cowardice, etc. However, this narration is mursal, which is considered weak according to the hadith scholars (muhaddithin).
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 2611
English Commentary: Explanation: 1: "Saraya" is the plural of "Sariyya." A "Sariyya" refers to a military expedition in which the Messenger of Allah (sallallahu alayhi wa sallam) did not personally participate. It is a detachment from the main army, consisting of up to four hundred soldiers at most.
Note:
(The narration of this hadith as "from Az-Zuhri, from the Prophet (sallallahu alayhi wa sallam)" is only correct as mursal (with a missing link), and it is also contrary to this divine verse: ﴿وَعَلِمَأَنَّفِيكُمْضَعْفًافَإِنيَكُنمِّنكُممِّئَةٌصَابِرَةٌيَغْلِبُواْمِئَتَيْنِ﴾ (Al-Anfal: 66), see: As-Saheehah, no. 986, Taraaji‘ Al-Albani: 152)
Source: Sunan al-Tirmidhi – Majlis ‘Ilmi Dar al-Da‘wah, New Delhi Edition, Page: 1555