Purity: Acts Not Requiring Ghusl for Janabah
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 356:
The ghusl for janābah is obligatory for obligatory prayers and suchlike, but it is not necessary for ṣalāt al‑mayyit, sajdatā al‑sahw, the prostration for offering thanks (sajdat al‑shukr), and for the obligatory prostrations of the Qur’an.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)