"O, that this too too sullied flesh would melt,
Thaw and resolve itself into a dew,
Or that the Everlasting had not fixed
His canon 'gainst self-slaughter! O God, God,
How weary, stale, flat, and unprofitable
Seem to me all the uses of this world!" (1.2.133-138).
Reasoning: Depressed over father's death, madness is making him lead to wanting to die (sullied flesh would melt).