Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا سُفْيَانُ، عَنْ عَمْرٍو، عَنْ جَابِرٍ، قَالَ كُنَّا يَوْمَ الْحُدَيْبِيَةِ أَلْفًا وَأَرْبَعَمِائَةٍ.Narrated Jabir:We were one thousand and four hundred on the Day of Al-Hudaibiya
From Sahih al-Bukhari, whose reports the scholars accept as authentic.