سنن النسائي

It was narrated from 'Amr bin Shu'aib, from his father that his grandfather said: "Hilal came to the Messenger of Allah (ﷺ) with one-tenth of the honey and asked him to protect a valley for him that was called Salabah. 'The Messenger of Allah (ﷺ) 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 they are just bees and anyone who wants to may eat of it."'