Brahma Sutras
ॐ अतोऽनन्तेन तथा हि लिङ्गम् ॐ ॥ ३-२-२७॥
Hence (the individual gets) unity with the Infinite; for such is the indicatory mark (in the Upanishad).
english translation
OM ato'nantena tathA hi liGgam OM ॥ 3-2-27॥
hk transliteration by Sanscript