Shiva Purana
शौचमाभ्यंतरं विद्यान्न बाह्यं शौचमुच्यते ॥ अंतः शौचविमुक्तात्मा शुचिरप्यशुचिर्यतः ॥ ५७ ॥
Purity too is the internal one. External purity is not enough. A man though physically pure is not pure if he is devoid of inner purity.
english translation
zaucamAbhyaMtaraM vidyAnna bAhyaM zaucamucyate ॥ aMtaH zaucavimuktAtmA zucirapyazuciryataH ॥ 57 ॥
hk transliteration by Sanscript