Umar bin Naf' al-Dwy عمر بن نافع العدوي · The Book of Zakah

"Hilal came to the Messenger of Allah with one-tenth of the honey and asked him to protect a valley for him that was called Salabah. 'The Messenger of Allah protected that valley for him. When 'Umar bin Al-Khattab became the Khalifah, sufyan bin Wahb wrote the 'Umar and asked him (about that), and Umar wrote: 'If the gives me what he used to give to the Messenger of Allah, one-tenth of his honey, I will protect Salahab for him, otherwise…