Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
حَدَّثَنَا مُسْلِمٌ، حَدَّثَنَا أَبُو الأَشْهَبِ، حَدَّثَنَا أَبُو الْجَوْزَاءِ، عَنِ ابْنِ عَبَّاسٍ، رضى الله عنهما فِي قَوْلِهِ {اللاَّتَ وَالْعُزَّى} كَانَ الَّلاَتُ رَجُلاً يَلُتُّ سَوِيقَ الْحَاجِّ.Narrated Ibn `Abbas:(regarding His Statement about the Lat and the `Uzza: Lat was originally a man who used to mix Sawiq for the pilgrim)
From Sahih al-Bukhari, whose reports the scholars accept as authentic.