Placing others higher than ourselves

Liberation comes from placing others higher than ourselves, it does not come from requesting for the realisation of Buddhahood. Why does attaining Buddhahood or benefiting others come from placing other higher than ourselves?  Why do we naturally attain Buddhahood? In Mahayana Buddhism they say ‘As long as you have self-grasping you will not attain Buddhahood; your merits are incomplete. Your bodhicitta, your compassion is incomplete. Your merit will not manifest. But if you benefit sentient beings, the merit will manifest!’ And this is a natural law.

GN Rinpoche