योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-166, verse-39

इदं ब्रह्म घनं सर्वं चिन्मात्रघनमाततम् ।
परमार्थघनं शान्तं सर्वमेकघनं विदुः ॥ ३९ ॥

idaṃ brahma ghanaṃ sarvaṃ cinmātraghanamātatam ,
paramārthaghanaṃ śāntaṃ sarvamekaghanaṃ viduḥ 39

39. It is all the substance of Brahma and the essence of the great Intellect, which fills and pervades the whole; know therefore all these as one, with the substantiality of the Supreme spirit, and all as quiet and calm as itself.