Sahih al-Bukhari 5412

It is related that Sa'd said, "I remember when I was one of (the first) seven with the Prophet, may Allah bless him and grant him peace. We had no food except the leaves of the Hubla or the Habala* so that our stool was like that of sheep. Now the Banu Asad want to teach me about Islam. I would be lost then and my striving wasted." [*Hubla is the fruit of the 'Idah, a sort of thorny tree which is a sort of bean, and habala is the stock of a grape vine.]