Spiritual Retreat: Failing to Leave the Place of Iʿtikaf for an Obligation
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1755
If it is obligatory for a muʿtakif to leave the place of iʿtikāf – for example, to pay a debt that is obligatory for him, and the time to repay it is due, and he has the ability to repay it, and the lender wants it to be repaid; or, to accomplish something else that is obligatory for him and which requires him to leave – then in these cases, if he acts contrary to his duty and does not leave, he commits a sin but his iʿtikāf does not become invalid.
-Ayatullah Sistani, Practical Laws of Islam, Spiritual Retreat (Iʿtikāf)