• أَلَّفَ
• أَلْف
• إِلَٰف
• أَلَّفْتَ
• إِلَٰفهِمْ
• مُؤَلَّفَة
• يُؤَلِّفُ

Appears 19 times in the Quran.

1. 2:96 وَلَتَجِدَنَّهُمْ أَحْرَصَ ٱلنَّاسِ عَلَىٰ حَيَوٰةٍ وَمِنَ ٱلَّذِينَ أَشْرَكُوا۟ يَوَدُّ أَحَدُهُمْ لَوْ يُعَمَّرُ أَلْفَ سَنَةٍ وَمَا هُوَ بِمُزَحْزِحِهِۦ مِنَ ٱلْعَذَابِ أَن يُعَمَّرَ وَٱللَّهُ بَصِيرٌۢ بِمَا يَعْمَلُونَ

   And you will most certainly find them the greediest of men for life (greedier) than even those who are polytheists; every one of them loves that he should be granted a life of a thousand years, and his being granted a long life will in no way remove him further off from the chastisement, and Allah sees what they do.
   

2. 2:243 أَلَمْ تَرَ إِلَى ٱلَّذِينَ خَرَجُوا۟ مِن دِيَٰرِهِمْ وَهُمْ أُلُوفٌ حَذَرَ ٱلْمَوْتِ فَقَالَ لَهُمُ ٱللَّهُ مُوتُوا۟ ثُمَّ أَحْيَٰهُمْ إِنَّ ٱللَّهَ لَذُو فَضْلٍ عَلَى ٱلنَّاسِ وَلَٰكِنَّ أَكْثَرَ ٱلنَّاسِ لَا يَشْكُرُونَ

   Have you not considered those who went forth from their homes, for fear of death, and they were thousands, then Allah said to them, Die; again He gave them life; most surely Allah is Gracious to people, but most people are not grateful.
   

3. 3:103 وَٱعْتَصِمُوا۟ بِحَبْلِ ٱللَّهِ جَمِيعًا وَلَا تَفَرَّقُوا۟ وَٱذْكُرُوا۟ نِعْمَتَ ٱللَّهِ عَلَيْكُمْ إِذْ كُنتُمْ أَعْدَآءً فَأَلَّفَ بَيْنَ قُلُوبِكُمْ فَأَصْبَحْتُم بِنِعْمَتِهِۦٓ إِخْوَٰنًا وَكُنتُمْ عَلَىٰ شَفَا حُفْرَةٍ مِّنَ ٱلنَّارِ فَأَنقَذَكُم مِّنْهَا كَذَٰلِكَ يُبَيِّنُ ٱللَّهُ لَكُمْ ءَايَٰتِهِۦ لَعَلَّكُمْ تَهْتَدُونَ

   And hold fast by the covenant of Allah all together and be not disunited, and remember the favor of Allah on you when you were enemies, then He united your hearts so by His favor you became brethren; and you were on the brink of a pit of fire, then He saved you from it, thus does Allah make clear to you His communications that you may follow the right way.
   

4. 3:124 إِذْ تَقُولُ لِلْمُؤْمِنِينَ أَلَن يَكْفِيَكُمْ أَن يُمِدَّكُمْ رَبُّكُم بِثَلَٰثَةِ ءَالَٰفٍ مِّنَ ٱلْمَلَٰٓئِكَةِ مُنزَلِينَ

   When you said to the believers: Does it not suffice you that your Lord should assist you with three thousand of the angels sent down?
   

5. 3:125 بَلَىٰٓ إِن تَصْبِرُوا۟ وَتَتَّقُوا۟ وَيَأْتُوكُم مِّن فَوْرِهِمْ هَٰذَا يُمْدِدْكُمْ رَبُّكُم بِخَمْسَةِ ءَالَٰفٍ مِّنَ ٱلْمَلَٰٓئِكَةِ مُسَوِّمِينَ

   Yea! if you remain patient and are on your guard, and they come upon you in a headlong manner, your Lord will assist you with five thousand of the havoc-making angels.
   

6. 8:9 إِذْ تَسْتَغِيثُونَ رَبَّكُمْ فَٱسْتَجَابَ لَكُمْ أَنِّى مُمِدُّكُم بِأَلْفٍ مِّنَ ٱلْمَلَٰٓئِكَةِ مُرْدِفِينَ

   When you sought aid from your Lord, so He answered you: I will assist you with a thousand of the angels following one another.
   

7. 8:63 وَأَلَّفَ بَيْنَ قُلُوبِهِمْ لَوْ أَنفَقْتَ مَا فِى ٱلْأَرْضِ جَمِيعًا مَّآ أَلَّفْتَ بَيْنَ قُلُوبِهِمْ وَلَٰكِنَّ ٱللَّهَ أَلَّفَ بَيْنَهُمْ إِنَّهُۥ عَزِيزٌ حَكِيمٌ

   And united their hearts; had you spent all that is in the earth, you could not have united their hearts, but Allah united them; surely He is Mighty, Wise.
   

8. 8:65 يَٰٓأَيُّهَا ٱلنَّبِىُّ حَرِّضِ ٱلْمُؤْمِنِينَ عَلَى ٱلْقِتَالِ إِن يَكُن مِّنكُمْ عِشْرُونَ صَٰبِرُونَ يَغْلِبُوا۟ مِا۟ئَتَيْنِ وَإِن يَكُن مِّنكُم مِّا۟ئَةٌ يَغْلِبُوٓا۟ أَلْفًا مِّنَ ٱلَّذِينَ كَفَرُوا۟ بِأَنَّهُمْ قَوْمٌ لَّا يَفْقَهُونَ

   O Prophet! urge the believers to war; if there are twenty patient ones of you they shall overcome two hundred, and if there are a hundred of you they shall overcome a thousand of those who disbelieve, because they are a people who do not understand.
   

9. 8:66 ٱلْـَٰٔنَ خَفَّفَ ٱللَّهُ عَنكُمْ وَعَلِمَ أَنَّ فِيكُمْ ضَعْفًا فَإِن يَكُن مِّنكُم مِّا۟ئَةٌ صَابِرَةٌ يَغْلِبُوا۟ مِا۟ئَتَيْنِ وَإِن يَكُن مِّنكُمْ أَلْفٌ يَغْلِبُوٓا۟ أَلْفَيْنِ بِإِذْنِ ٱللَّهِ وَٱللَّهُ مَعَ ٱلصَّٰبِرِينَ

   For the present Allah has made light your burden, and He knows that there is weakness in you; so if there are a hundred patient ones of you they shall overcome two hundred, and if there are a thousand they shall overcome two thousand by Allah's permission, and Allah is with the patient.
   

10. 9:60 إِنَّمَا ٱلصَّدَقَٰتُ لِلْفُقَرَآءِ وَٱلْمَسَٰكِينِ وَٱلْعَٰمِلِينَ عَلَيْهَا وَٱلْمُؤَلَّفَةِ قُلُوبُهُمْ وَفِى ٱلرِّقَابِ وَٱلْغَٰرِمِينَ وَفِى سَبِيلِ ٱللَّهِ وَٱبْنِ ٱلسَّبِيلِ فَرِيضَةً مِّنَ ٱللَّهِ وَٱللَّهُ عَلِيمٌ حَكِيمٌ

    Alms are only for the poor and the needy, and the officials (appointed) over them, and those whose hearts are made to incline (to truth) and the (ransoming of) captives and those in debts and in the way of Allah and the wayfarer; an ordinance from Allah; and Allah is knowing, Wise.
    

11. 22:47 وَيَسْتَعْجِلُونَكَ بِٱلْعَذَابِ وَلَن يُخْلِفَ ٱللَّهُ وَعْدَهُۥ وَإِنَّ يَوْمًا عِندَ رَبِّكَ كَأَلْفِ سَنَةٍ مِّمَّا تَعُدُّونَ

    And they ask you to hasten on the punishment, and Allah will by no means fail in His promise, and surely a day with your Lord is as a thousand years of what you number.
    

12. 24:43 أَلَمْ تَرَ أَنَّ ٱللَّهَ يُزْجِى سَحَابًا ثُمَّ يُؤَلِّفُ بَيْنَهُۥ ثُمَّ يَجْعَلُهُۥ رُكَامًا فَتَرَى ٱلْوَدْقَ يَخْرُجُ مِنْ خِلَٰلِهِۦ وَيُنَزِّلُ مِنَ ٱلسَّمَآءِ مِن جِبَالٍ فِيهَا مِنۢ بَرَدٍ فَيُصِيبُ بِهِۦ مَن يَشَآءُ وَيَصْرِفُهُۥ عَن مَّن يَشَآءُ يَكَادُ سَنَا بَرْقِهِۦ يَذْهَبُ بِٱلْأَبْصَٰرِ

    Do you not see that Allah drives along the clouds, then gathers them together, then piles them up, so that you see the rain coming forth from their midst? And He sends down of the clouds that are (like) mountains wherein is hail, afflicting therewith whom He pleases and turning it away from whom He pleases; the flash of His lightning almost takes away the sight.
    

13. 29:14 وَلَقَدْ أَرْسَلْنَا نُوحًا إِلَىٰ قَوْمِهِۦ فَلَبِثَ فِيهِمْ أَلْفَ سَنَةٍ إِلَّا خَمْسِينَ عَامًا فَأَخَذَهُمُ ٱلطُّوفَانُ وَهُمْ ظَٰلِمُونَ

    And certainly We sent Nuh to his people, so he remained among them a thousand years save fifty years. And the deluge overtook them, while they were unjust.
    

14. 32:5 يُدَبِّرُ ٱلْأَمْرَ مِنَ ٱلسَّمَآءِ إِلَى ٱلْأَرْضِ ثُمَّ يَعْرُجُ إِلَيْهِ فِى يَوْمٍ كَانَ مِقْدَارُهُۥٓ أَلْفَ سَنَةٍ مِّمَّا تَعُدُّونَ

    He regulates the affair from the heaven to the earth; then shall it ascend to Him in a day the measure of which is a thousand years of what you count.
    

15. 37:147 وَأَرْسَلْنَٰهُ إِلَىٰ مِا۟ئَةِ أَلْفٍ أَوْ يَزِيدُونَ

    And We sent him to a hundred thousand, rather they exceeded.
    

16. 70:4 تَعْرُجُ ٱلْمَلَٰٓئِكَةُ وَٱلرُّوحُ إِلَيْهِ فِى يَوْمٍ كَانَ مِقْدَارُهُۥ خَمْسِينَ أَلْفَ سَنَةٍ

    To Him ascend the angels and the Spirit in a day the measure of which is fifty thousand years.
    

17. 97:3 لَيْلَةُ ٱلْقَدْرِ خَيْرٌ مِّنْ أَلْفِ شَهْرٍ

    The grand night is better than a thousand months.
    

18. 106:1 لِإِيلَٰفِ قُرَيْشٍ

    For the protection of the Qureaish--
    

19. 106:2 إِۦلَٰفِهِمْ رِحْلَةَ ٱلشِّتَآءِ وَٱلصَّيْفِ

    Their protection during their trading caravans in the winter and the summer--