Known sources of this statement
This statement was attributed to Sufyan a-Thawri by abu Laith as-Smarqandi in his Tanbeeh al-Ghafilyn bi ahadithi sayyid al-Mursalynتنبيه الغافلين بأحاديث سيد الأنبياء والمرسلين and imam al-Qurtobi in his known book a-Tadhkirah bi ahwal al-Mawta wa omor al-Akhirah التذكرة بأحوال الموتى وأمور الآخرة (which is your own source), both quoted it without a chain as a saying of Sufyan a-Thawri and commented it. (see also this link)
Comments on the meaning
- Imam al-Qurtobi commented the statement as follows (My own translation take it carefully):
هذا صحيح لأن الله غني كريم وابن آدم فقير مسكين محتاج في ذلك اليوم إلى حسنة يدفع بها سيئة إن كانت عليه، حتى ترجح ميزانه فيكثر خيره وثوابه.
this is correct (true/sahih) because Allah is Free of needs and Generous while the son of Adam is poor and in need of good deeds (hasanah) on the day of judgement, to take away (off) any bad deeds (sayyi'ah) which is counted on him, so that his balance will over weight and hiss good and rewards would get more
This goes along with Allah's words showing that Allah is forgiving if we've done wrong or wronged our selves:
And those who, when they commit an immorality or wrong themselves [by transgression], remember Allah and seek forgiveness for their sins - and who can forgive sins except Allah ? - and [who] do not persist in what they have done while they know. (3:145)
read also in surat al-Furqan:
Except for those who repent, believe and do righteous work. For them Allah will replace their evil deeds with good. And ever is Allah Forgiving and Merciful. (25:70)
which is also covered in a lot of ahadith (I will only point at a single source of each, there might be others) like this one on the authority of abu Bakr as Siddiq, this one which was narrated on the authority of abu Hurrairah and Bilal ibn Yassar ibn Zaid (a freed slave of the Prophet()), this narration on the authority of abu Hurrairah, this sahih narration on the authority of abu Hurrairah
You may also find in lonag ahadith on the issue of Ifk the statement:
.... for when a person confesses his sin and asks Allah for forgiveness, Allah accepts his repentance. ... (Sahih al-Bukhari)
So far this covers the first part of the comment of al-Qurtobi which is about wrongdoings one may harm oneself and for which one needs Allah's forgiveness.
When it comes to wrongdoings we have committed and where we have wronged other's we need their forgiveness first else we can't be sure that we will be paying for them on judgment day. Therefore on this day everybody will be keen not to loose any good deed, as this day is described as:
- O mankind, fear your Lord and fear a Day when no father will avail his son, nor will a son avail his father at all. Indeed, the promise of Allah is truth, so let not the worldly life delude you and be not deceived about Allah by the Deceiver. (31:33)
- On the Day a man will flee from his brother (80:34)
And his mother and his father (80:35)
And his wife and his children (80:36)
For every man, that Day, will be a matter adequate for him. (80:37)
there are many more verses one could quote her.
And here some of the related ahadith (this is just a selection out of many):
- The claimants would get their claims on the Day of Resurrection so much so that the hornless sheep would get its claim from the horned sheep. (Sahih Muslim)
- Do you know who is poor? They (the Companions of the Holy Prophet) said: A poor man amongst us is one who has neither dirham with him nor wealth. He (the Holy Prophet) said: The poor of my Umma would be he who would come on the Day of Resurrection with prayers and fasts and Zakat but (he would find himself bankrupt on that day as he would have exhausted his funds of virtues) since he hurled abuses upon others, brought calumny against others and unlawfully consumed the wealth of others and shed the blood of others and beat others, and his virtues would be credited to the account of one (who suffered at his hand). And if his good deeds fall short to clear the account, then his sins would be entered in (his account) and he would be thrown in the Hell-Fire. (Sahih Muslim)
- "When (the following) was revealed: 'Then, on the Day of Resurrection, you will be disputing before your Lord (39:31).' Az-Zubair said "O Messenger of Allah! We will repeat our disputes after what happened between us in the world?" He said: "Yes." So he said: "Indeed this is a very serious matter." (Jami' at-Tirmidhi)
See also this sahih hadith on the authority of abu Hurrairah, this interesting narration in al-Bukhari's al-Adab al-Mufrad, this one on the authority of 'Abdullah ibn Mas'ud about the first claimants between humans which will be decided and this one about a man complaining about his slaves on the authority of 'Aisha.
- Abu Laith as-Samarqandi commented by adding a statement of Ibrahim ibn Adham in a section entitled by the oppressed will be the successful on the day of Resurrection:
وَعَنْ إِبْرَاهِيمَ بْنِ أَدْهَمَ رَحْمَةُ اللَّهِ عَلَيْهِ أَنَّهُ قَالَ : لَا يَنْبَغِي لِلرَّجُلِ إِذَا كَانَ عَلَيْهِ دَيْنٌ أَنْ يَصْطَبِغَ بِالزَّيْتِ أَوْ بِأَقَلَّ مِنْهُ مَا لَمْ يَقْضِ دَيْنَهُ.
Ibrahim ibn Adham said: A man who is in debt shouldn't paint (his house) using oil or less then it unless he has paid his due.
Unfortunately I have no idea how to interpret this statement (about Oil etc.).
The subject of this statement(s) is about harming or wronging oneself which is quoted in many verses (one of the worst wrongdoings is of kurs shirk and kufr).