Where is self-denial mentioned in the Quran?

I studied several religions and they all have "self-denial" as a main aspect mentioned in their texts. Such as: *"If you cling to your life, you will lose it; but if you give up your life for me, you will find it."* **Christians' Bible - Matthew 10:39** *"Therefore the sages: They place themselves last, but end up in front."* **Taoists' Tao Te Ching - Chapter 7** I friend of mine told me, that this is also the case with the Quran. But he couldn't tell me where it is written. Can you please tell me (cite with the exact source and line numbers) where this can be found in the Quran? Thank you.