KAṬHA UPANISHAD · 1.2.16

एतद्ध्येवाक्षरं ब्रह्म एतद्ध्येवाक्षरं परम् ।
एतद्ध्येवाक्षरं ज्ञात्वा यो यदिच्छति तस्य तत् ॥ १६॥

etaddhyevākṣaraṃ brahma etaddhyevākṣaraṃ param ।
etaddhyevākṣaraṃ jñātvā yo yadicchati tasya tat ॥ 16॥

For this Syllable is Brahman, this Syllable is the Most High: this Syllable if one know, whatsoever one shall desire, it is his.