Narrated from Abdullah bin Umar (may Allah be pleased with them) that the Prophet Muhammad (peace and blessings of Allah be upon him) said: "Delaying the repayment of a debt by a wealthy person is injustice. And when you are referred to a wealthy person (for repayment), accept it, and do not make two sales in one sale." Imam Tirmidhi says:
1- The hadith of Abu Hurairah (may Allah be pleased with him) is Hasan Sahih.
2- Its meaning is that when any of you is referred to a wealthy person for the collection of a debt, he should accept it.
3- Some scholars say that when a person is referred to a wealthy person and he accepts the referral, the one who made the referral is absolved, and it is not permissible for the creditor to return to the one who made the referral. This is also the opinion of Shafi’i, Ahmad, and Ishaq bin Rahwayh.
4- And some scholars say: that «محتال علیہ» "the person to whom the referral was made," if there is a risk of loss of wealth due to his becoming insolvent, then it is permissible for the creditor to return to the original debtor. These people have deduced this from the statement of Uthman (may Allah be pleased with him) and others that the wealth of a Muslim is not lost.
5- Ishaq bin Rahwayh says: The meaning of this hadith «ليس على مال مسلم توي» "the wealth of a Muslim is not lost," is that when a creditor is referred to someone and considers him wealthy, but in reality he is poor, then in such a case the wealth of a Muslim will not be lost (and he can demand his wealth from the original debtor).