Khalid b. Umair reported:
I heard Uqba b. Ghazwan as saving: I found myself as the seventh amongst the seven who had been along with Allah's Messenger (ﷺ). We had nothing to eat but the leaves of hubla (a wild tree) until the corners of our mouths were injured.
Reference: Sahih Muslim 2967 c
In-book reference: Book 55, Hadith 21
USC-MSA web (English) reference(deprecated numbering scheme): Book 42, Hadith 7077