It is narrated from Sayyiduna Hudhayfah (may Allah be pleased with him) that he returned from Sayyiduna Umar (may Allah be pleased with him) and related that yesterday, when we were sitting in his company, he asked the noble Companions: "Has any of you heard a hadith from the Messenger of Allah (peace and blessings be upon him) about the tribulations that will arise before the Day of Judgment?" All of them replied: "We have all heard much from the Messenger of Allah (peace and blessings be upon him) about this." He said: "Perhaps you think I am referring to the tribulation of a man regarding his family and wealth?" The people said: "Yes." He said: "I am not asking about that. Those tribulations are erased by prayer, fasting, and charity. I am asking whether any of you has heard from the Messenger of Allah (peace and blessings be upon him) about those tribulations which will come with the intensity and force of the waves of the sea." Sayyiduna Hudhayfah (may Allah be pleased with him) says that upon hearing this, everyone fell silent. I understood that Sayyiduna Umar (may Allah be pleased with him) wanted to ask me. I said: "I have heard." He said: "Very good." Sayyiduna Hudhayfah (may Allah be pleased with him) says: Then I related that tribulations will continuously cover the hearts of people just as the reeds of a mat are closely joined together. The hearts that do not become familiar with these tribulations, that is, do not get involved in them, will have white dots placed upon them, and the hearts that become familiar with these tribulations, that is, get involved in them, will have black dots placed upon them. Until the hearts of people, that is, the people themselves, will become of two kinds. One kind will be those whose hearts will be clear like a polished stone; as long as the heavens and the earth remain, that is, until the Day of Judgment, no tribulation will be able to harm them. The other kind will be those whose hearts will be black and crooked (and at the same time, he turned his palm upside down to show this); such people will follow only their desires, and they will not consider any good as good or any evil as evil.