During the Nyung Nye retreat at Do Ngak Khunphen Ling, Geshe Losang Dhargye who is leading the retreat, suggested that we meditate on the Four Immeausurables between sessions.
Much has been written about this topic. I found an excellent teaching by Mindrolling Jetsün Khandro Rinpoche that begins by asking us what it means to be Buddhist. She challenges us to really consider the meaning of the four immeasurables and not just pay them lip service. Are we willing to do the the hard work to uproot our self cherishing minds and to put an end to bad habits such as blaming others for our problems? Are we willing to give up our fondness for these habits?
Rinpoche gives a detailed explanation of how to meditate on the four immeasurables beginning with creating the right kind of mind (like a fertile field) that can support such vast thoughts. The teaching wraps up with instructions for how to approach each of the four topics.
I also found this beautiful quote about the Four Immesaurables on the Chenrezig Project website:
The Buddha taught the following to his son Rahula, (from “Old Path, White Clouds” by Thich Nhat Hahn):
“Rahula, practice loving kindness to overcome anger. Loving kindness has the capacity to bring happiness to others without demanding anything in return.
Practice compassion to overcome cruelty. Compassion has the capacity to remove the suffering of others without expecting anything in return.
Practice sympathetic joy to overcome hatred. Sympathetic joy arises when one rejoices over the happiness of others and wishes others well-being and success.
Practice non-attachment to overcome prejudice. Non-attachment is the way of looking at all things openly and equally . . . This is because that is . . . Myself and others are not separate. Do not reject one thing only to chase after another.
I call these the four immeasurables. Practice them and you will become a refreshing source of vitality and happiness for others.”
Source: Chenrezig Project