Thus suicide forbidden in Quran and hadith…

Given that Allah promised to undertake the sustenance and any delay thereafter or withholding of any of its needs being merely for a trial, then there is no room for a person to take away the life that Allah has created for an important purpose and meticulously sustaining it each second for that purpose.  He prohibited the destroying of ones life in any manner as understood by the general meaning of the wording of this verse, “And do not throw (yourselves) with your own hands to destruction; but work (deeds of) excellence for verily Allah loves the people of excellence.”  [Surah Baqarah 2:195]   Thus we are ordered to not destroy ourselves rather to direct the mind and energies to doing good deeds that please Allah.  In another verse, “And do not kill yourselves. Surely, Allaah is Most merciful to you.”  [Surah Nisaa 4:29]

In fact the taking of even one life is regarded as the taking of the life of the whole of mankind, “Whoever kills a soul – unless for another soul or for corruption (vice and mischief spread) in the land – it is as if he had slain the whole of mankind.  And whoever saves one – it is as if he had saved the whole of mankind.” [Surah Ma’idah 5:32]  The noun, soul (nafs) in the verse is without the definite particle. In Arabic, an indefinite noun in a conditional clause gives the meaning of generality and comprehensiveness.  Thus, the verse is not only concerning the taking of a soul of another person but even ones own life for both are souls created and entrusted to us by Allah.  This is not only prohibited but strongly condemned as though he killed the whole of mankind.

The Messenger of Allah (May the peace and blessings be on him) also prohibited it as learnt from the following hadith.  "Whoever throws himself down from a mountain and kills himself, he will be in the Fire of Hell throwing himself down for ever and ever. Whoever drinks poison and kills himself will have the poison in his hand, drinking it in the Fire of Hell for ever and ever. Whoever kills himself with a piece of iron (i.e. a weapon) will have that piece of iron in his hand, stabbing himself in the stomach with it in the Fire of Hell forever and ever." (Compiled in Sahih Bukhari).