Bhagavad Gita 10.32

I am the beginning, the middle, and the end of creation; among sciences, I am the science of spirituality; I am the discussion among disputants.

सर्गाणामादिरन्तश्च मध्यं चैवाहमर्जुन।
अध्यात्मविद्या विद्यानां वादः प्रवदतामहम्॥

sargāṇāmādirantaśca madhyaṃ caivāhamarjuna|
adhyātmavidyā vidyānāṃ vādaḥ pravadatāmaham||

English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).