I came across this article today in Yoga International magazine written beautifully by Kelly McGonigal, she teaches yoga, meditation and psychology at Stanford. It's an easy read. I highly recommend both the article and the practice.
It’s natural to identify a desire as “I want” and an intention as “I will” or “I won’t.” But these phrases lack the truth of the commitment that comes from heartfelt desire and connection to one’s dharma. “A sankalpa isn’t a petition or a prayer,” Miller says, “It is a statement of deeply held fact, and a vow that is true in the present moment.”For this reason, your sankalpa—both the heartfelt desire and the specific intention—should be stated in the present tense. For example, rather than saying, “I want to be more compassionate,” your sankalpa might be, “Compassion is my true nature” or “I am compassion itself.” Rather than setting the intention, “I will not eat meat,” your specific sankalpa might be, “With compassion for my body and for other beings, I eat a vegetarian diet.” Stating your sankalpa in present tense acknowledges the tremendous will, energy, and truth that arrive with the discovery of your heartfelt desire. It also reminds you that whatever is required of you is already within you.
Read the full article here:
Inspired Intention | The Nature of Sankalpa.