What specific quotes in Hamlet alludes to him pretending to be mad?

In the end of Act 1 Hamlet has just discovered that his
fathered has been murdered by Claudius.  Unfortunately, it is a ghost that delivered
this fateful news and Hamlet can't just jump into a fight with Claudius and kill him in
an act of revenge for this father.  He must prove that the ghost is telling the truth
and is not a ghost merely in the guise of his father but is actually the devil tempting
him to do evil and damn his eternal soul.  To that end, Hamlet's plan is to
"put an antic disposition on."  He goes on to specifically
explain how he might start to act and what he might say in his 'crazy act' so as to not
alarm his friend, Horatio.  He says,

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That you, at such times seeing me, never
shall,

With arms encumb'red thus, or this
head-shake,

Or by pronouncing of some doubtful
phrase,

As "well, well, we know," or "We could, an if we
would,"

Or "If we list to speak," or "There be, an if they
might,"

Or such ambiguous giving
out,"

By explaining in a rational way what his
plan is he is clearly telling us that he just pretending to be
mad.