Imam Ali(ع): Beware of having desires prevail over your hearts. Its beginning is kingdom, and its end is destruction.

إيّاكُم وغَلَبَةَ الشَّهَواتِ عَلی قُلوبِكُم؛ فَإِنَّ بِدايَتَها مَلَكَةٌ، ونِهايَتَها هَلَكَةٌ.

Beware of having desires prevail over your hearts. Its beginning is kingdom, and its end is destruction.