جزاهُ جزاءَ سِنِمَّارٍ

Meaning

He rewarded him as Sinimmar was rewarded

Notes

The phrase refers to an ancient Arabic proverb for treacherous betrayal, where someone responds to loyalty or a favor with deadly harm. It originates from the architect Sinimmar, who built a magnificent palace for the King of Al-Hirah. Upon finishing, Sinimmar was cast to his death so that he would not build a palace like it for anyone.