The story continues of the boy and the king. So as narrated in the hadith

 The story continues of the boy and the king. 

So as narrated in the hadith, 

He said, 'Allah has saved me from them,' and he said to the king: 'You cannot kill me until you do what I command you to do.' The king asked, 'What is that?' He said, 'Gather all people in one place and tie me up to the trunk of a tree, then take an arrow from my quiver and say: With the Name of Allah, the Rubb of the boy; then shoot me. If you do that you will be able to kill me.' 'The king called the people in an open field and tied the young boy to the trunk of a tree. He took out an arrow from his quiver, fixed in the bow and said, 'With the Name of Allah, the Rubb of the young boy,' he then shot the arrow and it hit the boy's temple. The young boy placed his hand upon the temple where the arrow had hit him and died. The people then said: 'We believe in the Rubb of this young boy.' The king was told: 'Do you see what you were afraid of, by Allah it has taken place; all people have believed.' The king then commanded that trenches be dug and fire lit in them, and said: 'He who would not turn back from his (the young boy's) religion, throw him in the fire' or 'he would be ordered to jump into it.' They did so till a woman came with her child. She felt hesitant in jumping into the fire. The child said to her: 'O mother! Endure (this ordeal) for you are on the Right Path". [Muslim].

Riyadus saliheen. 

Book 1, Hadith 30.

This is associated with the ayah of Quran, 

Al-Buruj 85:7

وَهُمْ عَلَىٰ مَا يَفْعَلُونَ بِٱلْمُؤْمِنِينَ شُهُودٌ 

And they, to what they were doing against the believers, were witnesses. [1]

Al-Buruj 85:8

وَمَا نَقَمُوا۟ مِنْهُمْ إِلَّآ أَن يُؤْمِنُوا۟ بِٱللَّهِ ٱلْعَزِيزِ ٱلْحَمِيدِ 

And they resented them not except because they believed in Allāh, the Exalted in Might, the Praiseworthy,

These people stood firmly to their eeman until they died upon such path. 

May Allah grants us steadfastness of faith. Aamin