In order to protect themselves they built their houses inside the mountains. The people of Thamud passed their life with ease and comfort. However, they were not thankful to Allah for His many blessings, and they were proud. They thought that their good life was a result of their own strength. Instead of turning to Allah, they used to worship part of a mountain and offer sacrifices to it.
Allah sent Prophet Salih to the people of Thamud to guide them to the right path. He was from their own tribe, and was respected because he was kind-hearted and wise, even as a young man.
Prophet Salih invited the people to worship only Allah, Who was their Creator. He tried to teach them how useless it was to worship a mountain, which could not harm or help anyone. He reminded them that he was from their own tribe and had their best interests at heart. He said, "You are all my brothers. I am not saying anything that will harm you. Come and seek the forgiveness of Allah and He will answer your prayers and grant your wishes."
However, the people of Thamud turned a deaf ear to him. They said, "O Salih, we thought you were a sensible man. We saw in you signs of goodness and wisdom, and wanted to rely on your advice in difficult times. Why have you started talking this nonsense now? Do you want us to stop worshipping what our ancestors worshipped for a long time? We will never listen to you!"
Prophet Salih patiently tried to teach them the truth. He made it clear that he was only guiding them so they could benefit themselves, and he did not want anything from them. He said that his reward would come from Allah. He reminded them of the many blessings that Allah had given them. He warned them not to continue in their ways in case the punishment of Allah came on them.
When Prophet Salih had started his mission he was 16 years old. Although he continued to preach till he was 120 years old, his words were accepted by only a few people. Most of the people of Thamud called him names, saying he was a madman or a liar. Prophet Salih replied to them by saying, "O People, I am not a liar. I have clear arguments from Allah as a proof of my Prophethood."
The leaders of Thamud had not listened to Prophet Salih because they were afraid that he might become powerful and they would lose their position as heads in the community. They decided to make Prophet Salih look weak in front of the people.
Therefore, they challenged him to prove his words by bringing out a she-camel from the side of their holy mountain. Prophet Salih caused this miracle to happen with the permission of Allah. The people had never seen such a camel in their lives. On one day, it would drink all the water in the town and on the next it would allow the people to drink the water. On the day that the she-camel drank all the water, it would give the people as much milk as they wanted.
The Holy Qur'an says:
And to (the people of) Thamud, (we sent) their brother Salih. He said, "O my people, worship Allah. You have no god but Him. Indeed a clear proof from your Lord came to you. This she-camel of Allah is a Sign for you. Leave it free to graze on Allah's earth and do not harm her, otherwise you will be overtaken by a painful punishment. (Quran 7:73)This powerful miracle made a lot of people believe the words of Prophet Salih and they embraced his faith. It also made the leaders of the tribe worried because they knew that as long as the people could see the she-camel, they would listen to Prophet Salih. The cruel leaders decided to kill the animal, although Prophet Salih had warned them that the punishment of Allah would certainly come if they harmed the she-camel.
A few wicked men ambushed the she-camel when it was returning after drinking the water. One man shot an arrow at its leg and another came forward and cut the muscles of its back legs so that the she-camel fell down. Then a man called Qadar struck the animal's neck with his sword and killed it. Then they came to Prophet Salih and proudly said, "O Salih! Bring us the punishment if you really are a Prophet."
Prophet Salih told them that they had committed a great sin and asked them to return to their homes for three days and beg for Allah's forgiveness. But the people only laughed at him. After three days, Prophet Salih received a command from Allah to leave the town with his followers. Then the punishment of Allah came down on the people of Thamud. A great thunderbolt came from the sky and a powerful earthquake shook the town and totally destroyed the buildings and houses. The people fell down dead and the fire from the sky turned their bodies to ashes. No one was left alive in the town after that terrible day.
When Prophet Salih saw the tragic end of the people of his own tribe, he turned to their remains and said, "O People, I delivered to you the message of Allah and guided you to the right way, but you always thought I was your enemy."
The Holy Prophet has said, "The most wicked person from the olden times is the one who killed the innocent she-camel of Prophet Salih and the most wicked person in these times is the one who will murder Imam Ali."
(Courtesy of:- Shia Ithna asheri Madressa)