Musannaf Ibn Abi Shayba 16:780

Abu Bakr narrated to us, he said: Ibn Fudayl narrated to us, from Husayn, from Mughirah ibn Shubayl, from Qays ibn Abi Hazim, who said: Abu Bakr used to come out to us, and it was as if his beard was the blazing fire of *‘arfaj* (a desert shrub) from the henna and the *katam* (a plant used for dyeing).