Laksha Bilwarchana is one of the most auspicious and powerful Yagyas. Offering Bilva leaves to Lord Shiva is considered very sacred and medicinal. Shiva and Shakti are one and the same. They are the creators and Divine parents of the universe. Together, they represent the Purusha (Shiva) and Prakriti (Shakti). Offering Bilva Patra to Shiva and Shakti in the month of Kartika is considered the most sacred offering to Shiva and Shakti. The leaves of this Bilva tree have a great impact in worshiping Lord Shiva and Vishnu.
Bilva leaves are trifoliate by nature, resembling a trident, and representing the three gods Brahma (Creator), Vishnu (Preserver), and Shiva (Destroyer), or the three Gunas: Satva, Rajas, and Tamas. According to the ‘Sri Sookta’ these leaves are born from the penance of Goddess Mahalakshmi. Hence these leaves are dearest to Lord Vishnu.

According to the Skanda Purana, the Bilva tree grew from the sweat droplets of Goddess Parvati which fell on the “Mandrachal mountain”. From there the Bilwa tree emerged. She resides as Girija in the roots of the tree, as Maheshwari in its trunk, as Dakshayani in its branches, Parvati in its leaves, Katyayani in its fruit and as Gauri in its flowers. Therefore as Parvati resides in Her various forms in this tree, Shiva is extremely fond of its leaves. It is a symbol of Shiva. Offering one bilva leaf is equivalent to offering a 1000 lotuses, says the Siva Purana.

बिल्वाणांदर्शनंपुण्यंस्पर्शनंपापनाशनं, अघॊरपापसंहारम्ऎकबिल्वंशिवार्पणं
Bilvanam darshanam punyam sparshanam papa nashanam
Aghora papa samharam eka bilvam shivarpanam
Offering a single Bilwa leaf to Lord Shiva, knowing that gazing upon and touching the Bilwa tree can cleanse even the gravest of sins.