Hadith 8:3199
Abu Bakr narrated to us, he said: Waki' narrated to us, he said: Sufyan narrated to us, from Jabir, from Abu Ja'far, he said: The days of Tashriq were only named as such because they used to dry [meat] in the sun.
حدثنا أبو بكر قال نا وكيع قال نا سفيان عن جابر عن أبي جعفر قال إنما سميت أيام التشريق أنهم كانوا يشرقون في الشمس