Verse 1.4.2

देवा वै मृत्योर्बिभ्यतस्त्रयीं विद्यां प्राविशंस्ते छन्दोभिरच्छादयन्यदेभिरच्छादयंस्तच्छन्दसां छन्दस्त्वम् ॥ १.४.२ ॥

devā vai mṛtyorbibhyatastrayīṃ vidyāṃ prāviśaṃste chandobhiracchādayanyadebhiracchādayaṃstacchandasāṃ chandastvam || 1.4.2 ||

2. The gods and goddesses were afraid of death, so they took refuge in the rites and rituals of the three Vedas. They covered themselves, as it were, with mantras. Because they covered themselves with mantras, the mantras came to be known as chandas.

Word-for-word explanation:

Devāḥ, the gods and goddesses; vai mṛtyoḥ bibhyataḥ, are afraid of death; trayīm vidyām prāviśan, they took refuge in the three Vedas [i.e., they decided to perform Vedic rites and rituals in order to escape death]; te, they; chandobhiḥ acchādayan, covered themselves with the mantras; yat, because; ebhiḥ,

Commentary:

In ancient times the gods and goddesses decided to perform the sacrifices mentioned in the three Vedas to save themselves from death. It was as if they took ‘cover’ behind the Vedic mantras. It is from this word ‘cover’ (acchādan) that the mantras have come to be known as chandas.