The Number Forty in the Ahadith
Here are a few ahadith that use the number forty.
 Kurayb – who was a freed slave of ‘Abdullah ibn ‘Abbas – reports that a son of Ibn ‘Abbas died in Qudayd (or maybe ‘Usfan). He told me, “O Kurayb. See how many people have gathered outside.” I went out and found that quite a few people had gathered for him. So I informed him. He said, “Do you say they are around forty?” I said, “Yes.” He said, “Take him out (the dead son). For I have heard the Prophet peace be on him say, ‘No Muslim dies and forty men stand up for Prayers for him – such as those who do not associate anything with Allah – but Allah accepts their intercession for him.’” (Muslim)
Note: That is, the Prayer that is offered for the dead, is accepted and the dead Muslim forgiven.
 The Prophet said, “Dajjal will appear in my Ummah and stay for forty. (I do not know [says the narrator] forty days, forty months or forty years). Then Allah will sent down `Isa the son of Maryam. He would look like `Urwah ibn Mas`ud. He will go after him and kill him. Then people will live for seven years in such a condition that there will be no enmity between two people. Then Allah will send a cold wind from the Syrian side and none will remain on the face of the earth who had an atom of good in him, or faith, but it will kill him. Until, if one of you enters into the heart of a mountain, it will enter after him and kill him.” He (the narrator) said, “I heard it from the Prophet.” Then he added, “Then the worst of people will be left behind as light and as unworthy as birds and beasts of prey. They will not know good as good, and will not treat an evil as evil. Then Shaytan will appear to them and say, ‘Will you not respond?’ They will ask, ‘What do you command us?’ He will command them to worship idols. And in that situation too they will be in good provision and well-being. Then the Trumpet will be blown. No one will hear it but he will bend his neck (to listen). The first to hear it will be a man repairing his water-trough for camels. He will fall unconscious. And the people will fall unconscious. Then Allah will send – or maybe he said, Allah will bring down – rains like dew – or maybe he said like a shadow (the doubt coming from Nu`man). With that their bodies will start growing (i.e., the dead bodies). Then the Trumpet will be blown a second time and lo, they will be up, waiting. Then it will be said, ‘O people. Up, unto your Lord. And, hold them up, for, they will be questioned.’ Then it will be said, ‘Bring out the deputation to the Fire.’ It will be asked, ‘How many?’ It will be said, ‘Of every thousand, nine hundred and ninety-nine.’ He said, ‘That is the day which will render young lads into old men. That will be the day when the shank will be uncovered.’” (Muslim)
 Said the Prophet: “When Allah created Adam, He touched his back and there fell off his back all the souls of his progeny that He was to create until the Day of Standing. He placed a spot of Light on the forehead of each of them and then presented them to Adam. He asked, ‘Who are these my Lord?’ He said, ‘These are your progeny.’ Among them he saw someone whose bright spot on his forehead pleased him. He asked, ‘My Lord! Who is this?’ He answered, ‘This is one of the last of your Ummah to appear as your progeny. He will be called Da’ud.’ He asked, ‘My Lord! What’s the age You have determined for him?’ He answered, ‘Sixty years.’ He said, ‘My Lord! Add up to him from my age, forty years.’
“When Adam had completed his age the angel of death came to him. He asked, ‘Am I not left with another forty years of my life?’ He answered, ‘Did you not gift it to your son Da’ud?’
“The Prophet said, ‘Thus Adam disputed and his progeny disputed. Adam forgot and his progeny forgot. Adam committed an error, and his progeny committed errors.’” (Tirmidhi)
 Abu Juhaym reported the Prophet as having said, “If someone crossing a person in Prayers knew what will be upon him (of the retribution) it would be better for him to wait for forty, rather than cross him.”
Abu al-Nadr added, “I don’t know whether he said forty days, forty months or forty years.” (Tirmidhi)
That is, he wasn’t sure of the figure and so he dropped it from the main narrative.
 ‘Abdullah ibn Mas‘ud narrated, “Said the Prophet, and he was the truthful and the one confirmed as truthful: ‘The creation of one of you is collected together in the womb of his mother for forty days. Then he becomes a clot of blood in as many days. Then he is like a chewed flesh in as many days. Then Allah sends an angel who blows the spirit into him. And four things are commanded to be written: his provision, his age, his deeds, and whether he will be fortunate or wretched. And by Him besides Whom there is no god, one of you does the deeds of the people of Paradise until there isn’t a yard (of distance) between him and it (i.e., Paradise). But the decree overcomes him and he ends up as of deeds of the people of the Fire and he enters into it. And one of you does the deeds of the people of the Fire, until there remains between him and it (i.e., the Fire) a yard (of the distance). Then the decree overcomes him and he ends up as of deeds of the people of Paradise and enters into it.” (Tirmidhi)
When a school master predicts that a student will fail the test, and actually allots him poor marks, the student is not absolved of his own responsibility. The master knew from his manner of studies, that this one was not going to get through. The prediction by the master should have actually increased the resolve of the student and he should have studied harder to get through with flying colors. But, if the student treats the warning as a judgment and makes no effort for the reason that the decree against him has already been pronounced, then he has no one to blame at the end of the affair except himself.
Allah has sent His Messenger and has made it clear to His creation what will make them fail the test, and what will help them get through. Now the ball is, so to say, in their court. And consistency till the last breath is the guarantor of a good end.
 ‘Abdullah ibn ‘Amr says the Prophet said, “There are forty qualities, of which the topmost is a man allowing his goat (to another for milk and other benefits) – whatever of these (forty) qualities that a man puts to practice, hoping to be rewarded, and testifying to the tryst, but Allah will thereby admit him into Paradise.” (Abu Da’ud)
This is a complicated hadith. The Prophet speaks of forty qualities, or good acts, that win a man Paradise if he hopes to win it and fears the Day of Resurrection. However, the Prophet did not mention the rest, but just one, perhaps because he knew his Companions would work out the rest themselves. The one he mentioned pertains to a man lending off his goat to another needy person who could keep it, benefit from it and return when the need is over. The Prophet used the word topmost, but perhaps he meant the top of the list, which may not be in order of importance.
 Anas b. Malik says, “The Prophet fixed for us removal of pubic hair, clipping of the nails and shortening of the moustaches as at least once in forty days.” (Abu Da’ud)