Manasika puja - mental puja Shiva

Manasika puja is more powerful than the outer puja with flowers, etc. Arjuna thought Bhima did not perform any kind of worship. He was proud of his outward worship of Lord Siva. He brought bilva leaves. But Bhima mentally offered Lord Siva the leaves of the bilva of all the bilva trees of the whole world.

He performed manasika puja to Lord Siva. The servants of Lord Siva did not have time to remove the leaves of the bilva offered by Bhima from the head of Lord Siva. One day, Arjuna saw a large crowd of people carrying baskets with bilva leaves. He thought to himself that these leaves should be the ones that he offered as an offering to Lord Siva, and asked people: “Brothers, where do you get these bilva leaves from?” They replied: "O Arjuna, these leaves are an offering to our Lord Siva from Bhima with the help of his manasika puja." Arjuna was surprised. He learned that manasika-puja is more powerful than outward worship, and that Bhima was more devoted than he. His pride was broken. He became very humble.
Manasika puja can be performed by advanced students. Beginners should definitely worship with flowers, sandalwood paste, incense, etc.

One man brought in only one rotten fruit of a roadside plant and a handful of small peas in Mayasika puja. Oh miserable beggar! Even in manasika puja, he could not be generous and free.

In the end, mentally repeat: “No matter what action I perform with my body, speech, mind, feelings, intellect or my own nature, I offer all this to the Supreme Lord.” This will clear your heart and eliminate the signs of expectation of reward.