Vijnana Bhairava Tantra
ध्यानं हि निश्चला बुद्धिर्निराकारा निराश्रया । न तु ध्यानं शरीराक्षिमुखहस्तादिकल्पना ॥ १४६ ॥
When the intellect becomes steady, formless and without any support, meditation is verified. Imagination of the form of the divine with a body, eyes, mouth, hands, etc. is not meditation.
english translation
dhyAnaM hi nizcalA buddhirnirAkArA nirAzrayA । na tu dhyAnaM zarIrAkSimukhahastAdikalpanA ॥ 146 ॥
hk transliteration by Sanscript