Mahāmudrā is the highest inner significance of the bKa’ brgyud sect, passed on to Nāropa by the adept of later Tantric Buddhism in India, Tilopa, and was brought into Tibet by the Tibetan translator Marpa. This paper examines the philosophy of Tilopa himself, regarded as the founder of bKa’ brgyud Mahāmudrā. I compare two poems: 1. the Tillopādasya dohākoṣa, which is considered as his autograph written by Apabhraṃśa; and 2. the Phyag rgya chen po ’i man ngag, which is extant only in Tibetan translation. This text is the source of many Mahāmudrā teachings and is well known as “Ganges Mahāmudrā” in the West.