योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-211, verse-7

प्रतिरात्रं प्रतिदिनं पुरः पश्चादुपर्यधः ।
पश्यस्यालोकयँल्लोकानपश्यंश्च न पश्यसि ॥ ७ ॥

pratirātraṃ pratidinaṃ puraḥ paścāduparyadhaḥ ,
paśyasyālokayaṃllokānapaśyaṃśca na paśyasi 7

7. Are all visible to you both by day and night, and above, below, behind and ever before you, if you will but look at them with the eyes of your mind; but if you shut your mental eye against spirituality, you can never have the sight of spirit presented before your view.