Imam Sadiq (peace be upon him): When Allah wills to resurrect creation, He causes the sky to rain upon the earth for forty days, so the veins and sinews come together and the flesh grows. Jibra'il came to the noble Messenger (peace be upon him and his family), took his hand and brought him to the Baqi' cemetery. They came to a grave; he called out to its occupant and commanded him to rise by the permission of Allah. A man with white hair and a white face, with dust settled on his face, came out of the grave saying الْحَمْدُ لِلَّهِ وَ اللَّهُ أَکْبَر [Praise be to Allah and Allah is the Greatest]. Jibra'il said to him: "Return to your place by the permission of Allah." Then they went to another grave, and he ordered its occupant to come out by Allah's command. A black-faced man came out of the grave saying يا حَسْرَتَاه يا وَاوَيْلَاه [Alas, my regret! Oh, woe!]. Then Jibra'il said to the Prophet (peace be upon him and his family): "People will be resurrected like this on the Day of Judgement — the believers will utter الْحَمْدُ لِلَّهِ وَ اللَّهُ أَکْبَر [Praise be to Allah and Allah is the Greatest] upon their tongues, and the disbelievers will say يا حَسْرَتَاه وَ وَاوَيْلَاه [Alas, my regret! Oh, woe!]."