First lessons in Islamic manuals of catechism are matters of cleanliness. Subjects taught first in the book of cleanliness include: which are clean, what is clean and what is not clean, what people need to be cleansed from, how they should clean, and which water should they use to clean. Muslims are required to perform ablution ("wudu") before every prayer, and are recommended to stay in the state of ablution at all times. A ritual bath ("ghusl") is performed on Fridays before the Friday Prayer ("Juma"). Ritual baths are recommended for spiritual purity, also after committing a sin, and are necessary for those who have washed a funeral. Special attention is given to cleaning homes before the arrival of guests or before feasts (Eid al-Fitr and Eid al-Adha), and holy days and nights.