By "araq" he means a basket that holds fifteen saa.
حدثنا موسى بن إسمعيل حدثنا أبان حدثنا يحيى
يعني بالعرق زنبيلا يأخذ خمسة عشر صاعا
No references are available.
[Its isnad is daif] Bayhaqi transmitted it: 7/390, from the hadith of Abu Dawud through this route. Aban is Ibn Yazid Attar, and Yahya is Ibn Abu Kathir, who is a mudallis and narrated using "an" (indicating possible concealment in the chain).