and if you are on a journey and cannot find a scribe then let there be a pledge taken then if one of you entrust the other let the one who is entrusted discharge his trust and let him be afraid of allah his lord. and conceal not the evidence for he who hides it surely his heart is sinful. and allah is allknower of what you do.
وإن كنتم على سفر ولم تجدوا كاتبا فرهان مقبوضة فإن أمن بعضكم بعضا فليؤد الذي اؤتمن أمانته وليتق الله ربه ولا تكتموا الشهادة ومن يكتمها فإنه آثم قلبه والله بما تعملون عليم