Explanation
The Hadīth of ‘Amr ibn al-Āas (may Allah be pleased with him) which includes the subject of conveying glad tidings and congratulating because it bears a story. The summary of this great story is that some of his companions were present with him while he was in the throes of death. He cried profusely and turned his face towards the wall as he was about to depart this world, so his son said to him: Why are you crying so long as the Prophet (may Allah's peace and blessings be upon him) had given you the glad tidings of entering Paradise? He said: O my son, I was in three different states (in this world). Then he described these three states. First, he used to hate the Prophet so much and there was no one on the face of the earth who hated him more, and wished he could catch him and kill him, and that was extreme disbelief. He remained like that until Allah instilled love for Islam in his heart. So, he went to the Prophet and said: O Messenger of Allah, extend your right hand so that I may give you my pledge of Islam. The Prophet (may Allah's peace and blessings be upon him) who was the best of all people in terms of manners, extended his hand, but ‘Amr withdrew his hand, not out of arrogance, but rather to ascertain what he was about to say. The Prophet asked him: What is the matter? He said: O Messenger of Allah, I have a condition (for embracing Islam). The Prophet asked: What is your condition? He said: That Allah forgive all my previous disbelief and sins. That was his biggest worry,(may Allah be pleased with him) fearing that Allah would not forgive him due to what he had done previously. So the Prophet (may Allah's peace and blessings be upon him) said to him: Do you not know that Islam wipes out what precedes it, and that migration wipes out what precedes it, and that the pilgrimage wipes out what precedes it? Three things wipe out all sins: Islam: it wipes out what precedes it according to the text of the Qur’an; Allah, the Exalted, says: {Say to those who have disbelieved [that] if they cease, what has previously occurred will be forgiven for them. But if they return [to hostility] - then the precedent of the former [rebellious] nations has already taken place} [Sūrat al-Anfāl: 38]. Hijrah: when one's homeland is a land of disbelief and he emigrates from it, this action wipes out what preceded it. Hajj: it wipes out what preceded it, as the Prophet (may Allah's peace and blessings be upon him) said: "The accepted Hajj has no reward but Paradise." So ‘Amr (may Allah be pleased with him) pledged allegiance to the Prophet and loved him intensely, so much so that the Prophet became the dearest of all people to him and he could never take a good look at him out of reverence for him. Glorified is Allah who turns the hearts! In the past, he hated him so much that he wished to kill him, and now he is not even able to lift his eyes to him out of reverence for him, and is not able to describe him because he never fully stared at him out of awe and respect. ‘Amr (may Allah be pleased with him) said that if he had died in the first state, he would have been from the dwellers of Hellfire. Then he said that if he had died in the second state, he could have hoped to be from the dwellers of Paradise. Notice his cautious choice of words; he was definitive in saying that if he had died in the first state, he would have been from the dwellers of Hellfire; but when it came to the second state, due to his intense fear, he said that if he had died in that state: "I could have hoped to be from the dwellers of Paradise," and he did not say: "I would have been from the dwellers of Paradise," since the confirmation of admittance to Paradise is a difficult thing to make. Then he said that, afterwards, he was entrusted with many affairs – being a ruler and a leader – and there occurred the incident of the battle with Mu‘āwiyah and others, and ‘Amr ibn al-‘Ās was known to be one of the shrewdest and most intelligent men among the Arabs. So he said: I fear that what had occurred after the second state might have nullified my deeds. Then he gave orders that no wailer (a woman who wails and laments the deceased) should follow his funeral, and that after they bury him, they should remain at his grave for as long as it would take them to slaughter a camel and distribute its meat, until he had answered the questions of the messengers of his Lord, meaning the angels who come to the dead person after he is buried. When the dead person is buried, two angels come to him and make him sit upright in his grave and ask him three questions: Who is your Lord? What is your religion? Who is your Prophet? So, ‘Amr ibn al-‘Ās (may Allah be pleased with him) ordered his family to stand by his grave for a time interval equal to the time it would take them to slaughter a camel and divide its meat, to seek solace and comfort in their presence. This is evidence that the deceased person can sense the presence of his family, and it was confirmed from the Prophet (may Allah's peace and blessings be upon him) that the deceased person hears the sound of their footsteps when they are leaving after his burial. Though the sound of sandals as they beat the ground is almost inaudible, the deceased hears it as the mourners depart after burying him. It was confirmed from the Prophet (may Allah's peace and blessings be upon him) in a sound Hadīth that when he buried a dead person, he used to stand over his grave and say: "Seek forgiveness for your brother and ask for steadfastness for him because he is being asked right now." So, when the dead person is buried, it is recommended to stand over his grave and say: "O Allah, make him firm (thrice); O Allah, forgive him (thrice)." Whenever the Prophet (may Allah's peace and blessings be upon him) said "Salām" (greetings of peace), he used to say it thrice; and whenever he made a supplication, he used to repeat it thrice. In short, the son of Āmr Ibn al-‘Ās said to him: "The Prophet (may Allah's peace and blessings be upon him) gave you the glad tidings of being admitted to Paradise", and he said this as a way of giving glad tidings and congratulating for it.