أَشْقَاهَا (The most wretched of them): The most wretched persons from Thamud’s people and the most disbelieving and rejecting of the Prophet Saleh (pbuh) and the most bold to kill the camel. They were nine of the most wretched people. Allah (swt) says:

 {وَكَانَ فِي الْمَدِينَةِ تِسْعَةُ رَهْطٍ يُفْسِدُونَ فِي الْأَرْضِ وَلَا يُصْلِحُونَ }

(And there were in the city nine family heads causing corruption in the land and not amending [its affairs].) (Al-Naml: 48)

They were people of absolute corruption, who did not know integrity and insisted on corruption and defended it, if they saw something right, they corrupted it and disagreed with its people. This is the nature of corrupt people, because amendment damages their benefits.