The sequence of the chapters
Revealed to the prophet (pbuh)
First time
the first verses of Al-Alaq chapter
which is chapter 96
(without Basmalah)
Basmalah =Besm Allah Al-Rahman Al-Raheem
(In the Name of Allah ,the Beneficent, the Merciful)
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Second time
the first verses of Al-Qalam chapter
which is chapter 68
(without Basmalah)
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Third time
the first verses of Al-Muzzamel chapter
which is chapter 73
(without Basmalah)
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Fourth time
Al-Muddather Chapter was revealed with these verses
("74.1": O you who are clothed!
"74.2": Arise and warn,
"74.3": And your Lord do magnify,
"74.4": And your garments do purify,
"74.5": And uncleanness do shun,
"74.6": And bestow not favors that you may receive again with increase,
"74.7": And for the sake of your Lord, be patient.
"74.8": For when the trumpet is sounded,
"74.9": That, at that time, shall be a difficult day,
"74.10": For the unbelievers, anything but easy.
"74.11": Leave Me and him whom I created alone,
"74.12": And give him vast riches,
"74.13": And sons dwelling in his presence,
"74.14": And I adjusted affairs for him adjustably;
"74.15": And yet he desires that I should add more!
"74.16": By no means! surely he offers opposition to Our revelations.
"74.17": 1 will make a distressing punishment overtake him.
"74.18": Surely he reflected and guessed,
"74.19": But may he be cursed how he plotted;
"74.20": Again, may he be cursed how he plotted;
"74.21": Then he looked,
"74.22": Then he frowned and scowled,
"74.23": Then he turned back and was big with pride,
"74.24": ~Then he said: This is naught but enchantment, narrated (from others);
"74.25": This is naught but the word of a mortal.
"74.26": 1 will cast him into hell.
"74.27": And what will make you realize what hell is?
"74.28": It leaves naught nor does it spare aught.
"74.29": It scorches the mortal.
"74.30": Over it are nineteen.)
after this verse (which contains the number ninteen)
Al-Basmalah which contains of 19 letters in the Arabic font

was revealed in this chapter
( In the name of Allah, the Beneficent, the Merciful.
"1.1": All praise is due to Allah, the Lord of the Worlds.
"1.2": The Beneficent, the Merciful.
"1.3": Master of the Day of Judgment.
"1.4": Thee do we serve and Thee do we beseech for help.
"1.5": Keep us on the right path.
"1.6": The path of those upon whom Thou hast bestowed favors. Not (the path) of those upon whom Thy wrath is brought down, nor of those who go astray.)