According to Hindu tradition, ‘Shravan’ month is the fifth month of the Hindu lunar calendar and one of the holiest months of the year. This auspicious month is dedicated to Lord Shiva's worship. The month of ‘Shravan’ begins with the first rains of the monsoon season.
The bel tree is considered a very sacred and holy tree in the Hindu religion. In Sanatan Vedic Dharma, the trifoliate form of the Bel leaves of this tree is believed to represent the 'trinetra,' or three eyes, of Lord Shiva and also symbolises the Trishul. According to Hindu mythology, the leaf also represents the holy trinity—Bramha, Vishnu, and Maheshwar.
The Bel leaf is known to be Lord Shiva’s favourite. The Shiva Purana says that this leaf is among the six divine articles used to worship Lord Shiva.
According to the Skanda Purana, when sweat droplets fell from the goddess Parvati's forehead, a tree was born on the great Mandrachal mountain. Then, Devi Parvati named the tree Bilva' and said that she resided in the tree in all her forms.
As every part of the Bel tree is said to contain the goddess Parvati, it is considered an ideal tree to worship Lord Shiva. It is said that even if one touches the Bel Patra, he or she will be freed from all negativity, sins, and ailments.
While choosing the Belpatra to offer to Lord Shiva or Shivlinga, always make sure that many leaves have chakras and stripes, which should not be used in worship. It is said that Belpatra, containing Chakra and Vajra, is considered fragmented.
While offering Belpatra on Shravan Somvar (Monday), make sure that the leaves are not cut or torn from anywhere. If you have not been able to collect more Bel leaves, then one Belpatra can also work, but it should not be torn from anywhere.