Who is more shameless in this world,
Than one who abandons to samsara’s ocean of suffering
All the mothers who have tenderly cared for him since beginningless time
And instead strives toward the peace of a solitary nirvana?
—Shechen Gyaltsap Pema Namgyal
In each of our lives since beginningless time, our mother carried us within her body for nine months. She took care of us when we were helpless babies; she gave us food, education, and protection. In return, we feel love and gratitude for her kindness.
Why not extend our respect and appreciation for our mother to everyone else? If we take a broader perspective, we can consider that, within the countless existences we have lived, every being has been our mother at one time or another. Don’t they also deserve our kindness now? We can extend the same debt of gratitude that we owe our present mother to all sentient beings. By doing so, we naturally begin to develop a deep concern for the happiness of others, and this feeling makes sense to us.
We take the refuge vow not just for our own sake, but also for the sake of all sentient beings. This is bodhichitta, or the altruistic mind, which aims for the enlightenment of all sentient beings.
From The Great Medicine That Conquers Clinging to the Notion of Reality: Steps in Meditation on the Enlightened Mind, by Shechen Rabjam, pages 53–54