Sayyiduna Abdullah bin Sakhr bin Lawdhan (may Allah be pleased with him), who was one of those whom the Prophet (peace and blessings be upon him) sent to Yemen with the governors, states: When the Prophet (peace and blessings be upon him) sent Sayyiduna Mu'adh (may Allah be pleased with him) to Yemen as a teacher, he said to him: I know of your trials in the religion, and I declare gifts pure for you; if you are given anything as a gift, accept it. When Sayyiduna Mu'adh (may Allah be pleased with him) returned, he had thirty head (of animals, or slaves) that had been given to him as gifts.
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir, and its chain contains a narrator, Sayf bin Umar al-Tamimi, who is da'if (weak). Other routes of this narration with good (jayyid) chains have already preceded in (the chapter on) bankruptcy and interdiction.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البيوع / 6741