45. Al-Hijr was the capital city of the people of Thamud, and its ruins are found near the modern city of Al-Ula which is to the north west of Al-Madinah, and lies on the route from AI-Madinah to Tabuk. Though the caravans had to pass through the valley of Al-Hijr, the Prophet (peace be upon him) had forbidden the Muslims to stay in the valley on their journey.
When Ibn Batutah reached there in the eighth century of Hijrah on his way to Makkah, he wrote: I have seen the buildings of Thamud hewed into red mountains; the paintings look so bright as if they have been put on only recently, and rotten bones of human beings are found in them even today." See (E.N. 57 of Surah Al-Aaraf).
46. That is, their strong and secure buildings, which they had hewed into the mountains, could not protect them from the blast.
47. This was to reassure the Prophet (peace be upon him) that ultimately he would come out successful because he was propagating the truth, and the entire universe was based on truth. Such an assurance was urgently needed because at that time falsehood appeared to be triumphant over the truth. This implies: O Prophet, do not worry at all at the apparent success of falsehood for this is temporary. Likewise the difficulties, the obstacles and the troubles in the way of truth are not permanent. Take courage, and have confidence in the cause of the truth and you will triumph over falsehood because the whole system of the universe is akin to truth and averse to falsehood. Therefore, truth is permanent and falsehood is perishable. Refer to (E.Ns 25-26, 35-39 of Surah Ibrahim).
48. These attributes of Allah have been mentioned to reassure the Prophet (peace be upon him) as if to say: As Allah is the Creator, He has complete power over all his creatures, and no one is able to escape His punishment. Moreover, He is All-Knowing. He is fully aware that you are exerting your utmost for their reform, and He knows also their evil machinations against your efforts for reform. Therefore, you need not worry on this account, but you should wait patiently and with confidence that at the appropriate time they will be dealt with justly.