Bukhari

Hadith Commentary:
➊ The total number of Muslims was between three hundred and ten and three hundred and nineteen.
➋ For recruitment in battle, only adult young men were taken.
➌ Bara’ (radi Allahu anhu) and Abdullah ibn Umar (radi Allahu anhu) were not recruited due to their young age.
➍ Their ages were between 13 and 14 years.
➎ In the Battle of Badr, the number of disbelievers was either one thousand or seven hundred and fifty, and they also had sufficient weapons, yet Allah granted the Muslims a clear victory.
➏ Talut was a king of Israel, in whose army Dawud (alayhis salam) was also included; the opposition was with a disbeliever named Jalut, whose army was large, but Allah granted victory to Talut.

Hadith Commentary:
At the time of the Battle of Badr, Abdullah ibn Umar (radi Allahu anhu) was thirteen years old. Despite his desire for jihad, he and Bara’ ibn Azib (radi Allahu anhu) were not granted permission. He was included in the Battle of Khandaq (the Trench). Similarly, in the Battle of Uhud, Ibn Umar (radi Allahu anhu) was not included, even though at that time he was fourteen years old. The Messenger of Allah (sallallahu alayhi wa sallam) would include in battle only those who had reached maturity. In the Battle of Badr, the number of disbelievers was around seven hundred and fifty or about one thousand, and they also had sufficient weaponry, whereas the Muslims numbered three hundred and ten or three hundred and nineteen. Their weapons were also not complete. Despite this, Allah, the Exalted, granted Islam and the people of Islam dominance. Even today, if the spirit of Badr is revived, then Allah’s help and His support can be with the Muslims.