Mus'ab bin Sa'd narrates that Ibn Umar (may Allah be pleased with them both) went to visit Abdullah bin Amir when he was ill, and he said: O Ibn Umar, will you not pray for me? He said: "I heard the Messenger of Allah (peace and blessings be upon him) say: Allah does not accept prayer without purification, nor charity from ill-gotten wealth", while you have been the governor of Basrah.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13209