Sa'id bin Abi Maryam said: I said to Attaf bin Khalid: What do you say, was Sayyiduna Ammar bin Yasir (may Allah be pleased with him) an ally of yours? He replied: Rather, he is our mawla (client).
Al-Tabarani recorded it, and its chain is munqati' (broken); its chain contains Attaf, about whom there is disagreement.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 15581