Bhagavad Gita · 10.14

सर्वमेतदृतं मन्ये यन्मां वदसि केशव।न हि ते भगवन्व्यक्तिं विदुर्देवा न दानवाः॥

sarvam etad ṛitaṁ manye yan māṁ vadasi keśhava na hi te bhagavan vyaktiṁ vidur devā na dānavāḥ

O Keshava, I accept as true everything you tell me. Neither the gods nor the demons, O Lord, can comprehend your personality.

— Bhagavad Gita 10.14

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)