How should bilva leaves be offered to Śiva — and can they be reused?

offer whole three-leaflet bilva leaves, washed and unbroken; tradition allows the same bilva to be washed and offered again.

The three leaflets of the bilva are seen as Śiva’s three eyes, or the three guṇas, or the trident. Choose leaves where all three leaflets are intact, wash them, and offer them on the liṅga with the stalk towards you and the smooth upper side touching the liṅga, saying “Oṁ Namaḥ Śivāya”. Many write “Rām” or “Oṁ” on the leaf with sandal paste.

Bilva is unusual in one way: tradition says it does not become stale or impure, so a leaf can be washed and offered again if fresh ones are not available. That is a great help in cities.

Many families avoid plucking bilva on Mondays, Amāvasyā, Saṅkrānti and certain tithis such as Caturthī, Aṣṭamī and Caturdaśī, so they pick leaves the day before. Pluck gently, never stripping the tree, and offer a prayer to the tree itself.

Source: Śiva Purāṇa tradition; common practice · Bilva can be washed and re-offered

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