“There were servants in Abal Hassan Ar-Ridha’’s (a.s.) home who were Slavic and Roman. Abul Hassan’s (a.s.) room was near theirs. One night Imam Ar-Ridha’ (a.s.) heard them say in the Slavic and Roman languages, ‘We used to donate blood once a year when we were in our own towns. However, we have never donated any blood for the many years that we have been here.’ Then when the morning came, Abal Hassan Ar-Ridha’ (a.s.) called in some doctors and told them to take blood from each of those servants. He precisely instructed the doctors as to which of the veins to use for each of the servants. Then he (a.s.) told me, ‘O Yasir! You should not donate blood.’ However, I did not pay any attention to the Imam (a.s.) and donated blood. However, my hand swelled up and turned purple. Ar-Ridha’ (a.s.) asked me, ‘What has happened to you?’ I answered, ‘I donated blood.” The Imam (a.s.) asked, ‘Did I not admonish you against donating blood? Please bring your hand forward.’ I put my hand forward. Then the Imam (a.s.) rubbed his hands on my hand and spit on it. Then the Imam (a.s.) ordered me not to eat dinner for a while. I tried not to eat dinner at night as much as I could. Whenever I failed to do so and ate something for dinner, that pain returned.”