Purity: Timing of Ghusl and Delay for Istiḥāḍah

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 399:

For excessive istiḥāḍah, in case it is necessary for there not to be a delay between performing ghusl and prayers – as mentioned in Ruling 394 – then, if performing ghusl before the time for prayers has set in causes delay, that ghusl will be of no use for the purposes of performing the prayer and a mustaḥāḍah must perform ghusl again for the prayer. This ruling also applies to a woman who has medium istiḥāḍah.

-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)