I have a question on arhat.
Will an arhat still think that he is walking, he is drinking
water, he is running in his daily life.
Does an Arhat still think in terms or I, me and mine ?
Yes but they are not deluded into thinking that they exist. Just
like you can think santa claus, but you don't believe it
exists.
They think and speak 'I' for convenient communication purpose.
The words don't refer to something real.
http://www.accesstoinsight.org/lib/authors/jootla/wheel414.html#ch2
Other devas had more sophisticated queries. One deva, for
example, asked the Buddha if an arahant could use words that refer
to a self:
"Consummate with taints destroyed,
One who bears his final body,
Would he still say 'I speak'?
And would he say 'They speak to me'?"
This deva realized that arahantship means the end of rebirth and
suffering by uprooting mental defilements; he knew that arahants
have no belief in any self or soul. But he was puzzled to hear
monks reputed to be arahants continuing to use such
self-referential expressions.
The Buddha replied that an arahant might say "I" always aware of
the merely pragmatic value of common terms:
"Skillful, knowing the world's parlance,
He uses such terms as mere expressions."
The deva, trying to grasp the Buddha's meaning, asked whether an
arahant would use such expressions because he is still prone to
conceit. The Buddha made it clear that the arahant has no delusions
about his true nature. He has uprooted all notions of self and
removed all traces of pride and conceit:
"No knots exist for one with conceit cast off;
For him all knots of conceit are consumed.
When the wise one has transcended the conceived
He might still say 'I speak,'
And he might say 'They speak to me.'
Skillful, knowing the world's parlance,
He uses such terms as mere expressions." (KS I, 21-22; SN 1:25)