What is the meaning of: "And Thamud, who carved out rocks in the valley"?

The noble verse: "And Thamud, who hewed out the rocks in the valley" is syntactically connected to what precedes it, and it explains that Allah Almighty dealt with Thamud as He dealt with 'Ad. Thamud were the people of Salih, "who hewed out the rocks in the valley," meaning they cut and carved rocks in the valley of Al-Qura, where they used to carve out homes in the mountains to dwell in, and they were the first to do so. The purpose of mentioning these stories is to instill fear in the people of Mecca by demonstrating how Allah destroyed previous nations that were stronger than them.