Musannaf Ibn Abi Shayba 28:943

Waki’ narrated to us, he said: Isra’il narrated to us, from Abu Ishaq, from Harithah ibn Mudhrib al-‘Abdi, from ‘Umar, that he stipulated upon the People of the Covenant (Ahl al-Dhimmah) hospitality for a day and a night. If rain or illness detained them, then for two days. If they stayed longer than that, they would spend from their own wealth, and they would not be burdened except with what they could bear.