Al-Kāfi

Hadith 370
menstruation
2ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ مُحَمَّدِ بْنِ عِيسَى عَنْ يُونُسَ عَنْ عَبْدِ الله بْنِ سِنَانٍ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ الْسَّلام) قَالَ سَأَلْتُهُ عَنِ الْمَرْأَةِ تَحِيضُ وَهِيَ جُنُبٌ هَلْ عَلَيْهَا غُسْلُ الْجَنَابَةِ قَالَ غُسْلُ الْجَنَابَةِ وَالْحَيْضِ وَاحِدٌ.
2. Ali ibn Ibrahim has narrated from Muhammad ibn ‘Isa from Yunus from ‘Abd Allah ibn Sinan who has said the following: “I once asked abu ‘Abd Allah (a.s.), about a woman who experiences Hayd (menses) when she has had sexual relation if she needed Ghusl (bath) because of sexual relation. He (the Imam) said, ‘Ghusl (bath) for Hayd (menses) and sexual relation is one.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī