In the ancient times, when the customs and laws of purity were keenly observed, the sages laid down detailed guidance for the periods of impurity following certain events, especially death and birth. For those who did not bear the sacred marks, once they had changed their clothes, their impurity was to last for three nights. If such individuals belonged to the same family and all were without sacred marks, the period of impurity was shortened to a single night. Yet, for those who bore the sacred marks, the duration of impurity was not fixed, but rather irregular, varying according to circumstances. When it came to women, their period of impurity was determined by counting as many days as the number of months they had lived. However, for relatives who shared the same ritual oblations, as well as in the case of miscarriage, immediate purification was prescribed—the rites could be performed without delay. If a kinsman chose to act according to his own will, the prescribed period of impurity was three nights. For others, a single day of purification was sufficient, though in some remaining cases, three nights were to be observed. When impurity arose from the death of one burdened with accumulated sin, it could be removed by performing the subsequent rite, or, as some authorities declared, by the previous rite. In all cases, a person remained impure until the final rites for the deceased were completed. There was also a custom that, after a death, one might bathe a year later if desired, though immediate purification was always allowed, regardless of time or circumstance. For relatives who shared the same ritual oblations, three nights of impurity were observed, but this applied solely to the husband’s rites. When a child died before reaching two years of age, immediate purification was declared—no period of impurity needed to be observed. From the time a gift was given, the period of impurity lasted three nights; if more time had elapsed, it extended to ten nights. The same rule applied when impurity arose from either death or birth among those who shared the same water. For teachers and fellow students, a single night of impurity was prescribed. When a daughter was given in marriage or died in her father’s house, the father’s period of impurity lasted three nights. The same three-night period applied for one’s teacher, one’s wives, and other women. For a sub-teacher or a learned Brahmin who lived in one’s own village, a single day of impurity was observed. In the case of a wife who was not the chosen one, the period was one day, or even just one night. When a kinsman of the same lineage died, immediate purification was again prescribed. The rules varied according to caste: a Vaiśya would be purified after fifteen days, while a Śūdra required a month. Among them all, a Brāhmaṇa became purified after ten days of impurity. It was emphasized that each person must observe the period of impurity appropriate to their own caste and lineage, without any doubt or hesitation. For Vaiśyas, Kṣatriyas, and Brāhmaṇas, impurity was incurred through contact with Śūdras; while for Śūdras, Kṣatriyas, and Brāhmaṇas, impurity arose from contact with Vaiśyas. The period of impurity for a Kṣatriya was also specified in due order: ten nights, as declared by Brahmā, the lotus-born. If people had eaten or lived together, ten nights of impurity were to be observed. During this time, one was not to eat food or remain in the house where impurity prevailed. If a close relative (sapiṇḍa) touched a corpse, ten days of impurity followed. For a twice-born individual, ten days sufficed, while for a king, twelve days were required. Alternatively, all could achieve purification in six nights, or even three, according to certain authorities. After bathing and partaking of ghee, Brāhmaṇas and others were considered purified. If, out of affection, one touched another during their period of impurity, the same length of impurity was to be observed by the one who touched. Purification could also be achieved by bathing with clothes on, touching fire, and partaking of ghee. For a Śūdra, three days of impurity were prescribed, or alternatively, a hundred exercises of breath-control could be performed to achieve the same result. In general, impurity lasted three nights, or, in some instances, it was remembered as lasting just one day. Thus did the sages of old prescribe the observances for purity, ensuring that each person, according to their role and circumstance, maintained the sanctity of their life and lineage.