Shiva Purana
यावत्फलं च तत्पूर्णं सर्वज्ञस्तु यथा वदेत् ॥ रागाज्ञानादिभिर्दोषैर्ग्रस्तत्वादनृतं वदेत् ॥ २३ ॥
As long as the fruit is complete, the omniscient should speak as he pleases. Because he is overcome by evils such as passion and ignorance he should speak lies.
english translation
yAvatphalaM ca tatpUrNaM sarvajJastu yathA vadet ॥ rAgAjJAnAdibhirdoSairgrastatvAdanRtaM vadet ॥ 23 ॥
hk transliteration by Sanscript