Spiritual Retreat: Leaving the Place of Iʿtikaf to Perform Ablution (Wuduʾ)
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1744
Leaving the place of iʿtikāf to perform ablution (wuḍūʾ) for an obligatory prayer within its prescribed time (adāʾ) is permitted, even if the time for the prayer has not yet set in. Leaving to perform wuḍūʾ for an obligatory qaḍāʾ prayer – in case there is ample time for performing it – is problematic [i.e. based on obligatory precaution, one must not leave in this case].
-Ayatullah Sistani, Practical Laws of Islam, Spiritual Retreat (Iʿtikāf)