Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
حَدَّثَنَا مُسْلِمٌ، حَدَّثَنَا شُعْبَةُ، عَنْ عَبْدِ الْمَلِكِ، عَنْ عَمْرِو بْنِ حُرَيْثٍ، عَنْ سَعِيدِ بْنِ زَيْدٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " الْكَمْأَةُ مِنَ الْمَنِّ وَمَاؤُهَا شِفَاءُ الْعَيْنِ ".Narrated Sa`id Ibn Zaid:The Prophet (ﷺ) said, "Al-Kam'a is like the Manna (sweet resin or gum) (in that it grows naturally without human care) and its water is a cure for the eye diseases
From Sahih al-Bukhari, whose reports the scholars accept as authentic.