Belpatra is offered to Lord Shiva due to its deep religious significance. It is believed to be dear to Shiva, symbolizing his three eyes and trident. Offering Belpatra pleases the deity, helping devotees receive his blessings and fulfillment of their wishes. Visit Bhaktvatsal.com for more information.
https://www.bhaktvatsal.com/gyanganga/bhagavan-shiv-par-kyon-chadhaya-jata-hai-belapatra