CHĀNDOGYA UPANISHAD · 2.21.3

तद् एष श्लोकः ।
यानि पञ्चधा त्रीणि त्रीणि ।
तेभ्यो न ज्यायः परम् अन्यद् अस्ति ॥

tad eṣa ślokaḥ ।
yāni pañcadhā trīṇi trīṇi ।
tebhyo na jyāyaḥ param anyad asti ॥

And thus it is said in the following verse: There are the fivefold three (the three kinds of sacrificial knowledge, the three worlds &c. in their fivefold form, i. e. as identified with the hiṅkâra, the prastâva, &c.), and the other forms of the Sâman. Greater than these there is nothing else besides.'

F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)