2. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad ibn ‘Isa from Ja‘far ibn Muhammad ibn abu Zayd al-Raziy from his father from Salih ibn ‘Uqbah from his father who has said the following:

“I once sent a mule as a gift to abu ‘Abd Allah , but (on the way) it made the driver to fall off. I then decided to visit him (the Imam) and when we were in al-Madinah, we informed abu ‘Abd Allah , about it. He (the Imam) said, ‘You must make him (the driver) to sniff viola. He sniffed viola and recovered. He (the Imam) said, ‘O ‘Uqbah, viola is of cool condition in summer and warm in winter. It is soft to our followers and dry to our enemies. If people had known what is in viola, every Awqiyah (a certain measurement) would cost one dinar.’”