Vijnana Bhairava Tantra
पूजा नाम न पुष्पाद्यैर्या मतिः क्रियते दृढा । निर्विकल्पे महाव्योम्न्नि सा पूजा ह्यदरालयः ॥ १४७ ॥
Offering of flowers, etc. is not pooja, or worship, but making one's mind steady in mahakasha, the great void, (and thoughtless) in nirvikalpa is worship indeed. From such reverence, dissolution (of mind) takes place.
english translation
pUjA nAma na puSpAdyairyA matiH kriyate dRDhA । nirvikalpe mahAvyomnni sA pUjA hyadarAlayaH ॥ 147 ॥
hk transliteration by Sanscript