Assalamualaikum. I’m a treasurer of a student association in one of the educational institutions in this country. A long time ago in the 90s, there is a member who borrowed some money from the association under the previous administration and time passed by. When the association audited and updated their account, they found a record stating the loan to the member. Even if we track him and inform him of this, it’s uncertain as to whether he’ll remember that he borrowed money from the association. If the association decided to let it go, is it permissible for him to have used the association’s money? Hope for an answer.
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions and all those who follow his footsteps until the Last Day.
Debt according to the 4th Edition of Kamus Dewan  is money or others that is loaned to someone else.
In Arabic, it is known as al-qardh (القَرضَ). Al-Qardh lexically means cut. According to the al-Misbah al-Munir dictionary : ‘قَرَضْتُ الشَّيْءَ قَرْضًا’ means I cut something. The noun of this word means an item given to another person on loan. This word is used in Arabic for it (the debt) to cut the rights of ownership of the owner on the item.
According to the jurists, the terminology is giving over ownership of something to another person on the condition that the other person will return it without any additions. In Arabic, this process is named qardh for this process cuts the ownership rights to be given to the debtor. This is in line with the meaning of qardh lexically. 
Debt that is borrowed is obligatory to be settled according to the agreed sum and duration. Whoever is in debt is obligated to settle his debt when he is financially capable to do so. Rasullullah PBUH restricts the postponement of debt. From Abu Hurairah RA, the Messenger PBUH said:
مَطْلُ الْغَنِىِّ ظُلْمٌ وَإِذَا أُتْبِعَ أَحَدُكُمْ عَلَى مَلِىءٍ فَلْيَتْبَعْ
“Delay in payment by a rich man is injustice, but when one of you is referred for payment to a wealthy* man he should accept the reference.” 
In answering the above question, the main issue is the level of the authorization given to the trustee. Are they authorized to excuse a debtor from paying the debt and annulling it?
In our opinion, this issue should be discussed presenting the evidence and details of the matter. This is so that the truth of the matter can be identified. Likewise, it is best if there are witnesses to this debt issue. The purpose is so that the argument and evidence are clear. Originally, a person’s credibility to pay one’s debt is the main agenda in the dictionary life of a person.
We’d like to narrate a story of a person who intended to pay his debt from Abu Hurairah RA, he said:
عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَنَّهُ ذَكَرَ رَجُلًا مِنْ بَنِي إِسْرَائِيلَ سَأَلَ بَعْضَ بَنِي إِسْرَائِيلَ أَنْ يُسْلِفَهُ أَلْفَ دِينَارٍ فَقَالَ ائْتِنِي بِالشُّهَدَاءِ أُشْهِدُهُمْ فَقَالَ كَفَى بِاللَّهِ شَهِيدًا قَالَ فَأْتِنِي بِالْكَفِيلِ قَالَ كَفَى بِاللَّهِ كَفِيلًا قَالَ صَدَقْتَ فَدَفَعَهَا إِلَيْهِ إِلَى أَجَلٍ مُسَمًّى فَخَرَجَ فِي الْبَحْرِ فَقَضَى حَاجَتَهُ ثُمَّ الْتَمَسَ مَرْكَبًا يَرْكَبُهَا يَقْدَمُ عَلَيْهِ لِلْأَجَلِ الَّذِي أَجَّلَهُ فَلَمْ يَجِدْ مَرْكَبًا فَأَخَذَ خَشَبَةً فَنَقَرَهَا فَأَدْخَلَ فِيهَا أَلْفَ دِينَارٍ وَصَحِيفَةً مِنْهُ إِلَى صَاحِبِهِ ثُمَّ زَجَّجَ مَوْضِعَهَا ثُمَّ أَتَى بِهَا إِلَى الْبَحْرِ فَقَالَ اللَّهُمَّ إِنَّكَ تَعْلَمُ أَنِّي كُنْتُ تَسَلَّفْتُ فُلَانًا أَلْفَ دِينَارٍ فَسَأَلَنِي كَفِيلَا فَقُلْتُ كَفَى بِاللَّهِ كَفِيلًا فَرَضِيَ بِكَ وَسَأَلَنِي شَهِيدًا فَقُلْتُ كَفَى بِاللَّهِ شَهِيدًا فَرَضِيَ بِكَ وَأَنِّي جَهَدْتُ أَنْ أَجِدَ مَرْكَبًا أَبْعَثُ إِلَيْهِ الَّذِي لَهُ فَلَمْ أَقْدِرْ وَإِنِّي أَسْتَوْدِعُكَهَا فَرَمَى بِهَا فِي الْبَحْرِ حَتَّى وَلَجَتْ فِيهِ ثُمَّ انْصَرَفَ وَهُوَ فِي ذَلِكَ يَلْتَمِسُ مَرْكَبًا يَخْرُجُ إِلَى بَلَدِهِ فَخَرَجَ الرَّجُلُ الَّذِي كَانَ أَسْلَفَهُ يَنْظُرُ لَعَلَّ مَرْكَبًا قَدْ جَاءَ بِمَالِهِ فَإِذَا بِالْخَشَبَةِ الَّتِي فِيهَا الْمَالُ فَأَخَذَهَا لِأَهْلِهِ حَطَبًا فَلَمَّا نَشَرَهَا وَجَدَ الْمَالَ وَالصَّحِيفَةَ ثُمَّ قَدِمَ الَّذِي كَانَ أَسْلَفَهُ فَأَتَى بِالْأَلْفِ دِينَارٍ فَقَالَ وَاللَّهِ مَا زِلْتُ جَاهِدًا فِي طَلَبِ مَرْكَبٍ لِآتِيَكَ بِمَالِكَ فَمَا وَجَدْتُ مَرْكَبًا قَبْلَ الَّذِي أَتَيْتُ فِيهِ قَالَ هَلْ كُنْتَ بَعَثْتَ إِلَيَّ بِشَيْءٍ قَالَ أُخْبِرُكَ أَنِّي لَمْ أَجِدْ مَرْكَبًا قَبْلَ الَّذِي جِئْتُ فِيهِ قَالَ فَإِنَّ اللَّهَ قَدْ أَدَّى عَنْكَ الَّذِي بَعَثْتَ فِي الْخَشَبَةِ فَانْصَرِفْ بِالْأَلْفِ الدِّينَارِ رَاشِدًا
“The Prophet (ﷺ) said, “An Israeli man asked another Israeli to lend him one thousand Dinars. The second man required witnesses. The former replied, ‘Allah is sufficient as a witness.’ The second said, ‘I want a surety.’ The former replied, ‘Allah is sufficient as a surety.’ The second said, ‘You are right,’ and lent him the money for a certain period. The debtor went across the sea. When he finished his job, he searched for a conveyance so that he might reach in time for the repayment of the debt, but he could not find any. So, he took a piece of wood and made a hole in it, inserted in it one thousand Dinars and a letter to the lender and then closed (i.e. sealed) the hole tightly. He took the piece of wood to the sea and said: ‘O Allah! You know well that I took a loan of one thousand Dinars from so-and-so. He demanded a surety from me but I told him that Allah’s Guarantee was sufficient and he accepted Your guarantee. He then asked for a witness and I told him that Allah was sufficient as a Witness, and he accepted You as a Witness. No doubt, I tried hard to find a conveyance so that I could pay his money but could not find it, so I hand over this money to You.’ Saying that he threw the piece of wood into the sea till it went out far into it, and then he went away. Meanwhile, he started searching for a conveyance in order to reach the creditor’s country.
One day the lender came out of his house to see whether a ship had arrived bringing his money, and all of a sudden, he saw the piece of wood in which his money had been deposited. He took it home to use for fire. When he sawed it, he found his money and the letter inside it. Shortly after that, the debtor came bringing one thousand Dinars to him and said, ‘By Allah, I had been trying hard to get a boat so that I could bring you your money, but failed to get one before the one I have come by.’ The lender asked, ‘Have you sent something to me?’ The debtor replied, ‘I have told you I could not get a boat other than the one I have come by.’ The lender said, ‘Allah has delivered on your behalf the money you sent in the piece of wood. So, you may keep your one thousand Dinars and depart guided on the right path.’ ” 
Hopefully, this story will motivate us in striving to settle our debts. To close, once again we’d like to reaffirm that one’s debt even if it hasn’t been settled for a long time, it is obligatory for him to pay it back even if the creditor didn’t ask for it, especially if the debt is from the money of an association or general public, for it involves public property and not personal property. We end with e supplication:
اللَّهُمَّ اكْفِنِى بِحَلاَلِكَ عَنْ حَرَامِكَ وَأَغْنِنِى بِفَضْلِكَ عَمَّنْ سِوَاكَ
“O Allah, suffice me with what You have allowed instead of what You have forbidden, and make me independent of all others besides You.”