Raksha Bandhan falls on the Purnima of Shravana. A sister ties a thread on her brother's wrist; he gives her a gift and, in the older understanding, an undertaking of protection. The thread is the whole rite — the raksha sutra, a bond that binds the one who ties it and the one who wears it equally.

The older texts do not restrict the thread to siblings. It was tied by priests on patrons, by wives on husbands, by anyone on anyone whose protection was sought or offered. What survives in common practice is the sibling form.

The rakhi must not be tied during Bhadra. Because Shravana Purnima frequently begins with Bhadra running, the muhurat often opens only in the afternoon — the aparahna window is traditionally preferred, and pradosh is acceptable when aparahna is unavailable.

Two older legends sit behind the sibling rite. Yamuna tied a thread on her brother Yama, the lord of death; moved by it, he declared that whoever is bound by a sister's thread would become deathless — and so the thread came to mean protection from the worst thing there is. In the second, Lakshmi ties a rakhi on the demon-king Bali to whom Vishnu had bound himself as a doorkeeper; the thread makes Bali her brother, and a brother cannot refuse a sister's wish, so she asks for Vishnu back. The famous raksha-sutra mantra — 'by that thread which bound the mighty Bali' — remembers exactly this.

Raksha Bandhan falls on Shravana Purnima, at the height of the monsoon, when rivers are full and disease spreads easily — a season when a token of care and a check on one another had real weight. The same full moon is Shravani / Upakarma, when the twice-born change the sacred thread and begin a fresh cycle of study, and Narali Purnima on the west coast, when fishing communities read the calming of the monsoon winds and return to the sea. The thread itself — cotton dyed in turmeric — carries the old antiseptic association of haldi.

The raksha sutra protects not by force but by obligation. A wall can be breached; a promise freely given is harder to break. In tying it the sister does not command protection — she places the brother under a bond he takes on willingly, and the binding falls equally on the one who ties and the one who wears. It is dharma made visible as a single thread: a relationship held not by blood alone but by a duty each accepts.

When Krishna cut his finger on the Sudarshana chakra, Draupadi tore a strip from her sari and bound the wound without a word. Krishna told her the debt would be repaid. Years later, when she was dragged into the Kaurava court and her sari pulled, it did not end — the cloth ran on and on, and she was not shamed. A strip of cloth given freely had returned as cloth without end.

Another telling: Indra, losing to the asuras, was given a thread by his wife Sachi, consecrated with her austerity and tied on his wrist. He went back and won. In the oldest sense the raksha sutra protects not by force but by obligation — it places the one who wears it under a promise, and a promise is harder to break than a wall.