Najibullah  is the title of Hazrat Dawood (AS) 

The holy book Zaboor revealed to Hazrat Dawood (AS)

Hazrat Dawood (AS) is buried in Israel.

Hazrat Dawood is called caliph of Allah.

Hazrat Dawood (AS) is mentioned in the Holy Quran for 16 times.

Bani Israel unanimously acknowledged Hazrat Dawood A.S as their king