Thus, when one’s consciousness is completely fixed on the Absolute Truth, the Supreme Personality of Godhead, one no longer sees duality, or internal and external reality. The example is given of the arrow maker who was so absorbed in making a straight arrow that he did not even see or notice the king himself, who was passing right next to him.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
तदैवमात्मन्यवरुद्धचित्तो न वेद किञ्चिद्बहिरन्तरं वा । यथेषुकारो नृपतिं व्रजन्त- मिषौ गतात्मा न ददर्श पार्श्वे
tadaivamātmanyavaruddhacitto na veda kiñcidbahirantaraṃ vā | yatheṣukāro nṛpatiṃ vrajanta- miṣau gatātmā na dadarśa pārśve
SB 11.9.13