وَإِن كُنتُمْ عَلَى سَفَرٍ وَلَمْ تَجِدُواْ كَاتِبًا فَرِهَانٌ مَّقْبُوضَةٌ فَإِنْ أَمِنَ بَعْضُكُم بَعْضًا فَلْيُؤَدِّ الَّذِي اؤْتُمِنَ أَمَانَتَهُ وَلْيَتَّقِ اللّهَ رَبَّهُ وَلاَ تَكْتُمُواْ الشَّهَادَةَ وَمَن يَكْتُمْهَا فَإِنَّهُ آثِمٌ قَلْبُهُ وَاللّهُ بِمَا تَعْمَلُونَ عَلِيمٌ
﴿٢٨٣﴾
سورة البقرة
(2/283) If you are on a journey and you do not find a scribe, then let there be a pledge taken (from the debtor) (this is sufficient); then he who is trusted should deliver his trust (his debt) and let him have piety (takwâ) towards Allah, his Lord, and do not conceal testimony, and whoever conceals it, his heart is surely sinful and Allah is the All-Knowing of what you do.
Surah Al-Baqarah