Mukhtasar Bukhari

Sayyiduna Bara’ (may Allah be pleased with him) says: The companions of the Prophet (peace and blessings of Allah be upon him) who were present at Badr narrated to me that their number was the same as those who were with Talut (the king) and crossed the river with him, and they were a little over three hundred and ten men. Sayyiduna Bara’ (may Allah be pleased with him) says: By Allah! None except the believers could cross the river with them. (See Surah Al-Baqarah, verse: 249)