Al-Hawala (the transference of a debt from one person to another. It is an agreement whereby a debtor is released from a debt by another becoming responsible for it). Can Hawala be rejected by the creditors after accepting it?
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكٌ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَطْلُ الْغَنِيِّ ظُلْمٌ، فَإِذَا أُتْبِعَ أَحَدُكُمْ عَلَى مَلِيٍّ فَلْيَتْبَعْ ".
Narrated Abu Huraira: The Prophet (ﷺ) said, "Procrastination (delay) in paying debts by a wealthy man is injustice. So, if your debt is transferred from your debtor to a rich debtor, you should agree."