Purity: Definition and Method of Istibrāʾ After Urination
Practical Laws of Islam as per the teaching of Ayatullah Sistani
Ruling 69
Istibrāʾ is a recommended (mustaḥabb) act performed by men after urinating in order to be confident that no urine is left in the urethra. It is performed in a number of ways; one way is as follows: after urinating, the anus is first purified if it has become impure; then, the middle finger of the left hand is slid three times from the anus up to the scrotum; then, the thumb is placed on the penis, and the forefinger is placed under the penis, and the thumb and forefinger are pulled three times along the penis up to the point of circumcision; finally, the end of the penis is pressed three times.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)