Whoever throws himself from a mountain and kills himself will be in Hellfire, falling down into it and abiding therein eternally forever

The Prophet (may Allah's peace and blessings be upon him) warned against intentionally taking one's own life in this world, stating that such a person will be punished in Hellfire on the Day of Judgment in the same manner by which he ended his life, as a fitting recompense. If someone threw himself off a mountain and died, he will continuously fall from the mountains of Hellfire into its valleys, abiding therein forever.

If someone drank poison to kill himself, he will have that poison in his hand, drinking it repeatedly in Hellfire, eternally. And if someone stabbed himself in the belly with a piece of iron, he will have that piece of iron in his hand, stabbing his belly repeatedly in Hellfire, abiding therein forever.