• أَسْلَفَتْ
• أَسْلَفْتُمْ
• سَلَف
• سَلَفَ

Appears 8 times in the Quran.

1. 2:275 ٱلَّذِينَ يَأْكُلُونَ ٱلرِّبَوٰا۟ لَا يَقُومُونَ إِلَّا كَمَا يَقُومُ ٱلَّذِى يَتَخَبَّطُهُ ٱلشَّيْطَٰنُ مِنَ ٱلْمَسِّ ذَٰلِكَ بِأَنَّهُمْ قَالُوٓا۟ إِنَّمَا ٱلْبَيْعُ مِثْلُ ٱلرِّبَوٰا۟ وَأَحَلَّ ٱللَّهُ ٱلْبَيْعَ وَحَرَّمَ ٱلرِّبَوٰا۟ فَمَن جَآءَهُۥ مَوْعِظَةٌ مِّن رَّبِّهِۦ فَٱنتَهَىٰ فَلَهُۥ مَا سَلَفَ وَأَمْرُهُۥٓ إِلَى ٱللَّهِ وَمَنْ عَادَ فَأُو۟لَٰٓئِكَ أَصْحَٰبُ ٱلنَّارِ هُمْ فِيهَا خَٰلِدُونَ

   Those who swallow down usury cannot arise except as one whom Shaitan has prostrated by (his) touch does rise. That is because they say, trading is only like usury; and Allah has allowed trading and forbidden usury. To whomsoever then the admonition has come from his Lord, then he desists, he shall have what has already passed, and his affair is in the hands of Allah; and whoever returns (to it)-- these arc the inmates of the fire; they shall abide in it.
   

2. 4:22 وَلَا تَنكِحُوا۟ مَا نَكَحَ ءَابَآؤُكُم مِّنَ ٱلنِّسَآءِ إِلَّا مَا قَدْ سَلَفَ إِنَّهُۥ كَانَ فَٰحِشَةً وَمَقْتًا وَسَآءَ سَبِيلًا

   And marry not woman whom your fathers married, except what has already passed; this surely is indecent and hateful, and it is an evil way.
   

3. 4:23 حُرِّمَتْ عَلَيْكُمْ أُمَّهَٰتُكُمْ وَبَنَاتُكُمْ وَأَخَوَٰتُكُمْ وَعَمَّٰتُكُمْ وَخَٰلَٰتُكُمْ وَبَنَاتُ ٱلْأَخِ وَبَنَاتُ ٱلْأُخْتِ وَأُمَّهَٰتُكُمُ ٱلَّٰتِىٓ أَرْضَعْنَكُمْ وَأَخَوَٰتُكُم مِّنَ ٱلرَّضَٰعَةِ وَأُمَّهَٰتُ نِسَآئِكُمْ وَرَبَٰٓئِبُكُمُ ٱلَّٰتِى فِى حُجُورِكُم مِّن نِّسَآئِكُمُ ٱلَّٰتِى دَخَلْتُم بِهِنَّ فَإِن لَّمْ تَكُونُوا۟ دَخَلْتُم بِهِنَّ فَلَا جُنَاحَ عَلَيْكُمْ وَحَلَٰٓئِلُ أَبْنَآئِكُمُ ٱلَّذِينَ مِنْ أَصْلَٰبِكُمْ وَأَن تَجْمَعُوا۟ بَيْنَ ٱلْأُخْتَيْنِ إِلَّا مَا قَدْ سَلَفَ إِنَّ ٱللَّهَ كَانَ غَفُورًا رَّحِيمًا

   Forbidden to you are your mothers and your daughters and your sisters and your paternal aunts and your maternal aunts and brothers' daughters and sisters' daughters and your mothers that have suckled you and your foster-sisters and mothers of your wives and your step-daughters who are in your guardianship, (born) of your wives to whom you have gone in, but if you have not gone in to them, there is no blame on you (in marrying them), and the wives of your sons who are of your own loins and that you should have two sisters together, except what has already passed; surely Allah is Forgiving, Merciful.
   

4. 5:95 يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ لَا تَقْتُلُوا۟ ٱلصَّيْدَ وَأَنتُمْ حُرُمٌ وَمَن قَتَلَهُۥ مِنكُم مُّتَعَمِّدًا فَجَزَآءٌ مِّثْلُ مَا قَتَلَ مِنَ ٱلنَّعَمِ يَحْكُمُ بِهِۦ ذَوَا عَدْلٍ مِّنكُمْ هَدْيًۢا بَٰلِغَ ٱلْكَعْبَةِ أَوْ كَفَّٰرَةٌ طَعَامُ مَسَٰكِينَ أَوْ عَدْلُ ذَٰلِكَ صِيَامًا لِّيَذُوقَ وَبَالَ أَمْرِهِۦ عَفَا ٱللَّهُ عَمَّا سَلَفَ وَمَنْ عَادَ فَيَنتَقِمُ ٱللَّهُ مِنْهُ وَٱللَّهُ عَزِيزٌ ذُو ٱنتِقَامٍ

   O you who believe! do not kill game while you are on pilgrimage, and whoever among you shall kill it intentionally, the compensation (of it) is the like of what he killed, from the cattle, as two just persons among you shall judge, as an offering to be brought to the Kaaba or the expiation (of it) is the feeding of the poor or the equivalent of it in fasting, that he may taste the unwholesome result of his deed; Allah has pardoned what is gone by; and whoever returns (to it), Allah will inflict retribution on him; and Allah is Mighty, Lord of Retribution.
   

5. 8:38 قُل لِّلَّذِينَ كَفَرُوٓا۟ إِن يَنتَهُوا۟ يُغْفَرْ لَهُم مَّا قَدْ سَلَفَ وَإِن يَعُودُوا۟ فَقَدْ مَضَتْ سُنَّتُ ٱلْأَوَّلِينَ

   Say to those who disbelieve, if they desist, that which is past shall be forgiven to them; and if they return, then what happened to the ancients has already passed.
   

6. 10:30 هُنَالِكَ تَبْلُوا۟ كُلُّ نَفْسٍ مَّآ أَسْلَفَتْ وَرُدُّوٓا۟ إِلَى ٱللَّهِ مَوْلَىٰهُمُ ٱلْحَقِّ وَضَلَّ عَنْهُم مَّا كَانُوا۟ يَفْتَرُونَ

   There shall every soul become acquainted with what it sent before, and they shall be brought back to Allah, their true Patron, and what they devised shall escape from them.
   

7. 43:56 فَجَعَلْنَٰهُمْ سَلَفًا وَمَثَلًا لِّلْءَاخِرِينَ

   And We made them a precedent and example to the later generations.
   

8. 69:24 كُلُوا۟ وَٱشْرَبُوا۟ هَنِيٓـًٔۢا بِمَآ أَسْلَفْتُمْ فِى ٱلْأَيَّامِ ٱلْخَالِيَةِ

   Eat and drink pleasantly for what you did beforehand in the days gone by.