Compassion and generosity must be accompanied by detachment. Expecting something in return for them is like doing business. If the owner of a restaurant is all smiles with his customers, it is not because he loves them but because he wants to increase his turnover. When we love and help others, it should not be because we find a particular individual likable but because we see that all beings, whether we think of them as friends or enemies, want to be happy and have the right to happiness.
The Fourteenth Dalai Lama, Tenzin Gyatso, in On the Path to Enlightenment: Heart Advice from the Great Tibetan Masters, page 80