Coming from Tibetan culture, it has a three-edged blade symbolizing the three poisons of the mind: attachment, aversion and ignorance. The Phurba would have the power to transform and "cure" these poisons.
It’s a powerful tool to ward off negative vibrations, to chase away evil spirits, or to combat the demon of the ego, commonly mentioned in Buddhist teaching. It also represents impermanence. To refer to its impermanence, it will be used in mandala-destroying rituals in the sand, mixing the grains of sand before dispersing them in the water.
Its etymology and form suggest that the Phurba was once an object used to fix something in the ground. Planted in the ground, the Phurba releases Evil from Mother Earth. Later, in the practice of Tibetan Tantric Buddhism, it was used as a dagger which bewitched evil spirits during the ceremony.
The Phurba is an object of power intervening on different levels of consciousness and considered as one of the Great Jewels of Tibetan Buddhism.