Karma Yoga. New York, 1896. Complete Works, 1: 109 - Swami Vivekananda

All the great systems of ethics teach absolute unselfishness as the
goal. When a man reaches this absolute selfishness, he is no more the
little Mr. So-and-so. He acquires infinite expansion. The little
personality which he had before is now lost to him for ever. He
becomes infinite. The attainment of this expansion is indeed the goal
of all religions and of all moral and philosophical teachings.

Karma Yoga. New York, 1896. Complete Works, 1: 109