Al-Baqarah 2:282

Ya ayyuha allatheena amanooitha tadayantum bidaynin ila ajalin musammanfaktuboohu walyaktub baynakum katibun bilAAadliwala ya/ba katibun an yaktuba kamaAAallamahu Allahu falyaktub walyumlili allatheeAAalayhi alhaqqu walyattaqi Allaha rabbahu walayabkhas minhu shay-an fa-in kana allathee AAalayhialhaqqu safeehan aw daAAeefan aw la yastateeAAuan yumilla huwa falyumlil waliyyuhu bilAAadli wastashhidooshaheedayni min rijalikum fa-in lam yakoonarajulayni farajulun wamraatani mimman tardawnamina ashshuhada-i an tadilla ihdahumafatuthakkira ihdahuma al-okhrawala ya/ba ashshuhadao itha maduAAoo wala tas-amoo an taktuboohu sagheeran awkabeeran ila ajalihi thalikum aqsatu AAindaAllahi waaqwamu lishshahadati waadnaalla tartaboo illa an takoona tijaratanhadiratan tudeeroonaha baynakum falaysa AAalaykumjunahun alla taktubooha waashhidoo ithatabayaAAtum wala yudarra katibun walashaheedun wa-in tafAAaloo fa-innahu fusooqun bikum wattaqooAllaha wayuAAallimukumu Allahu wallahubikulli shay-in AAaleem

O you who have believed, when you contract a debt for a specified term, write it down. And let a scribe write [it] between you in justice. Let no scribe refuse to write as Allāh has taught him. So let him write and let the one who has the obligation [i.e., the debtor] dictate. And let him fear Allāh, his Lord, and not leave anything out of it. But if the one who has the obligation is of limited understanding or weak or unable to dictate himself, then let his guardian dictate in justice. And bring to witness two witnesses from among your men. And if there are not two men [available], then a man and two women from those whom you accept as witnesses - so that if one of them [i.e., the women] errs, then the other can remind her. And let not the witnesses refuse when they are called upon. And do not be [too] weary to write it, whether it is small or large, for its [specified] term. That is more just in the sight of Allāh and stronger as evidence and more likely to prevent doubt between you, except when it is an immediate transaction which you conduct among yourselves. For [then] there is no blame upon you if you do not write it. And take witnesses when you conclude a contract. Let no scribe be harmed or any witness. For if you do so, indeed, it is [grave] disobedience in you. And fear Allāh. And Allāh teaches you. And Allāh is Knowing of all things.

O you who believe, when you transact a debt payable at a specified time, put it in writing, and let a scribe write it between you with fairness. A scribe should not refuse to write as Allah has educated him. He, therefore, should write. The one who owes something should get it written, but he must fear Allah, his Lord, and he should not omit anything from it.If the one who owes is feeble-minded or weak or cannot dictate himself, then his guardian should dictate with fairness. Have two witnesses from among your men, and if two men are not there, then one man and two women from those witnesses whom you like, so that if one of the two women errs, the other woman may remind her. The witnesses should not refuse when summoned. And do not be weary of writing it down, along with its due date, no matter whether the debt is small or large. That is more equitable in Allah’s sight, and more supportive as evidence, and more likely to make you free of doubt. However, if it is a spot transaction you are effecting between yourselves, there is no sin on you, should you not write it. Have witnesses when you transact a sale. Neither a scribe should be made to suffer, nor a witness. If you do (something harmful to them), it is certainly a sin on your part, and fear Allah. Allah educates you, and Allah is All-Knowing in respect of everything.