Muṇḍaka Upaniṣad · 1.2.7

प्लवा ह्येते अदृढा यज्ञरूपा अष्टादशोक्तमवरं येषु कर्म । एतच्छ्रेयो येऽभिनन्दन्ति मूढा जरामृत्युं ते पुनरेवापि यन्ति

plavā hy ete adṛḍhā yajñarūpā aṣṭādaśoktam avaraṃ yeṣu karma | etac chreyo ye'bhinandanti mūḍhā jarāmṛtyuṃ punar evāpi yanti

Frail are these boats of ritual form, eighteen in number, referred to as inferior. Those fools who delight in this as the highest good return again to old age and death.

Devastating critique of those who confuse means with end: rituals are not the ultimate goal.

Plavāḥ — frail, unstable boats. The rituals are precarious means of transport, not definitive supports.

Aṣṭādaśa… yajñarūpāḥ — eighteen ritual forms. The classic Vedic sacrifices, numbered as eighteen.

Avaraṃ — inferior, lesser. Ritual knowledge (aparā vidyā) is below the knowledge of Brahman (parā vidyā).

Mūḍhāḥ — fools, confused. Those who take the means for the end, the shadow for the substance.

Abhinandanti — delight in, rejoice in. Attachment to ritual results is the trap.

Jarāmṛtyuṃ punar evāpi yanti — return to old age and death. The cycle of saṃsāra continues; there is no liberation without higher knowledge.

The verse does not condemn ritual but confusing it with the final goal. The yogī uses everything as preparation, never as satisfaction.