Shiva Purana
द्विधा मत्पूजनं ज्ञेयं बाह्यमाभ्यंतरं तथा ॥ वाङ्मनःकायभेदाच्च त्रिधा मद्भजनं विदुः ॥ ४७ ॥
My worship shall be known to be two-fold: external and internal. My adorative service is three-fold, differing in view of speech, mind and body.
english translation
dvidhA matpUjanaM jJeyaM bAhyamAbhyaMtaraM tathA ॥ vAGmanaHkAyabhedAcca tridhA madbhajanaM viduH ॥ 47 ॥
hk transliteration by Sanscript