Ubayd bin Umayr narrates: Sayyiduna Abdullah bin Salam (may Allah be pleased with him) was sitting. He said something, and it was overheard by a man whom he did not want to hear it. So he turned to Sayyiduna Abu al-Darda (may Allah be pleased with him) and said: "Did you not hear the Prophet (peace and blessings be upon him) say: 'Whoever says something and wishes that it not be spread on his behalf, then it is a trust, even if the person concerned did not ask for it to be kept secret'?"
This narration was recorded by Imam al-Tabarani as a hadith narrated by Sayyiduna Abdullah bin Salam (may Allah be pleased with him). Its chain contains a narrator, Ubaydullah bin al-Walid al-Wassafi, who is matruk (abandoned).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 13167