Bhashya
देवा वै मृत्यो मारकात् बिभ्यत किं कृतवन्त इति,उच्यत— त्रयीं विद्या त्रयीविहित कर्म प्राविशन् प्रविष्टव-न्त , वैदिक कर्म प्रारब्धवन्त इत्यथ , तत् मृत्योस्त्राण मन्य-माना ।किंच, ते कर्मण्यविनियुक्तै छन्दोभि मन्त्रै जप-होमादि कुर्वन्त आत्मान कमान्तरेष्वच्छादयन् छादितवन्त ।यत् यस्मात् एभि मन्त्रै अच्छादयन्, तत् तस्मात् छन्दसा मन्त्राणा छादनात् छन्दस्त्व प्रसिद्धमेव ॥
In plain words
Fearing death, the great destroyer, what did the gods do? It is said that they took refuge in the threefold wisdom of the Vedas and the rituals prescribed by them. They began performing these sacred rites, believing they would shield them from death. Furthermore, using sacred meters and mantras not bound to specific rites, they engaged in silent chanting and fire offerings, wrapping themselves in these spiritual practices for protection. Because they covered and shielded themselves with these sacred verses, those verses are beautifully known as 'chandas'—that which covers and protects.
Close to the Sanskrit
The gods indeed, fearing death the killer, what did they do? It is said—they entered the threefold knowledge, the action ordained by the three Vedas; they entered, meaning they commenced Vedic ritual, thinking that to be protection from death. Furthermore, they, by means of meters, mantras not applied in ritual, performing silent recitation, fire offerings, etc., covered themselves in other actions, meaning they protected themselves. Because they covered themselves with these mantras, therefore, due to the covering of the mantras, the status of meters (chandas) is indeed well-known.