Purity: Direction of Washing in Immersive Wudu
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 261
In immersive wuḍūʾ, one must also wash his face and arms from top to bottom. Therefore, if at the time of immersing his face and arms in the water one makes the intention of wuḍūʾ, he must immerse his face forehead-first, and his arms elbow-first.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)