One verse

Srimad Bhagavatam 11.9.13

11.9.13

तदैवमात्मन्यवरुद्धचित्तो न वेद किञ्चिद् बहिरन्तरं वा । यथेषुकारो नृपतिं व्रजन्त- मिषौ गतात्मा न ददर्श पार्श्वे ॥ १३ ॥

tadaivam ātmany avaruddha-citto na veda kiñcid bahir antaraṁ vā yatheṣu-kāro nṛpatiṁ vrajantam iṣau gatātmā na dadarśa pārśve

tadā
at that time
evam
thus
ātmani
in the Supreme Personality of Godhead
avaruddha
fixed
cittaḥ
the mind
na
does not
veda
know
kiñcit
anything
bahiḥ
outside
antaram
inside
vā
either
yathā
just as
iṣu
of arrows
kāraḥ
a maker
nṛ-patim
the king
vrajantam
going
iṣau
in the arrow
gata-ātmā
being absorbed
na dadarśa
did not see
pārśve
right next to him

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.