Al-Ḥadth al-Aṣghar (Arabic: الحدث الأصغر, minor ritual impurity) is an act that invalidates wudu', or the state occurs for one as a result of invalidation of wudu and one is not allowed to perform the acts that are subject to wudu'.
Hadath is something that invalidates tahara (ritual purity). It is also used for the state that occurs for a person after certain acts, such as: urinating, janaba, hayd, or touching a dead body, and the person is not allowed to perform the acts that are subject to tahara. The rulings about hadath are discussed in jurisprudential books and manual of Islamic law. A person to whom a hadath has occurred is called muhdith.
Faqihs have divided hadath into al-hadath al-akbar (major ritual impurity) and al-hadath al-asghar (minor ritual impurity). By al-hadth al-asghar they mean what invalidates wudu', that includes:
- Expelling intestinal gas,
- Sleeping (deep enough that one ceases to see or hear),
- Things that cause the loss of intellect (such as insanity, intoxication, or unconsciousness),
- Minor istihada
- Najafī, Jawāhir al-kalām, vol. 1, p. 63.
- Shaykh al-Anṣārī, Kitāb al-tahāra, vol. 4, p. 43.
- Hāshimī Shāhrūdī, Farhang-i fiqh, vol. 3, p. 246.
- Fayḍ al-Kāshānī, Rasāʾil, vol. 2 , p. 22.
- Fayḍ al-Kāshānī, Muḥammad Ḥasan al-. Rasāʾil. Edited by Bihzād Jaʿfarī. Tehran: Madrisa-yi ʿĀlī-yi Shahīd Muṭahharī, 1429 AH.
- Hāshimī Shāhrūdī, Sayyid Maḥmūd. Farhang-i fiqh muṭābiq-i madhhab-i Ahl al-Bayt. Qom: Muʾassisat Dāʾirat al-Maʿārif Fiqh al-Islāmī, 1426 AH.
- Najafī, Sayyid Muḥammad ḥasan al-. Jawāhir al-kalām fī sharāyiʿ al-Islām. Edited by ʿAbbas Qūchānī & ʿAlī Ākhūndī. Beirut: Dār Iḥyāʾ al-Turāth al-ʿArabī, 1404 AH.
- Anṣārī, Murtaḍā. Kitāb al-ṭahāra. Qom: Kungira-yi Buzurgdāsht-i Shaykh al-Anṣārī, 1415 AH.