Mantra 3

यो ह वै प्रतिष्ठां वेद प्रति ह तिष्ठत्यस्मिंश्च लोकेऽमुष्मिंश्च चक्षुर्वाव प्रतिष्ठा ॥ ५.१.३ ॥

In plain words

He who knows the foundation stands firm in this world and in the world beyond. The eye is the foundation.