CHĀNDOGYA UPANISHAD · 1.4.2

देवा वै मृत्योर् बिभ्यतस् त्रयीं विद्यां प्राविशन् ।
ते छन्दोभिर् अच्छादयन् ।
यद् एभिर् अच्छादयंस् तच् छन्दसां छन्दस्त्वम् ॥

devā vai mṛtyor bibhyatas trayīṃ vidyāṃ prāviśan ।
te chandobhir acchādayan ।
yad ebhir acchādayaṃs tac chandasāṃ chandastvam ॥

The Devas, being afraid of death, entered upon (the performance of the sacrifice prescribed in) the threefold knowledge (the three Vedas). They covered themselves with the metrical hymns. Because they covered (khad) themselves with the hymns, therefore the hymns are called khandas.

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