If you are traveling and a scribe is not available, a collateral of some value may serve the purpose, or a bond shall be posted to guarantee repayment. If one is trusted in this manner, he shall return the collateral or the bond when due, and be mindful of Allah, his Lord. Do not withhold any testimony by concealing what you have witnessed. Anyone who withholds a testimony is noxious to his own sensitivity. Allah is Aware of all your actions.