The virtues of Abu Ayyub al-Azdi (may Allah be pleased with him), an ascetic Companion

It is narrated from Mus'ab bin Abdullah al-Zubayri that Sayyiduna Abu Ayyub Khalid bin Zayd bin Kulayb bin Tha'labah bin Abd Awf, who belonged to Banu Tamim bin Malik bin al-Najjar, took part in the Pledge of al-Aqabah, the Battle of Badr, all the campaigns, and the conquests of Iraq. He was also present with Sayyiduna Ali (may Allah be pleased with him) at the Battle of Siffin. Then he went to Syria, entered the land of the Romans as a warrior, and stayed at Constantinople.

It is narrated from Ibrahim bin Kathir: I heard Umarah bin Ghaziyyah say that Sayyiduna Abu Ayyub al-Azdi (may Allah be pleased with him) came to Sayyiduna Mu'awiyah (may Allah be pleased with him). Then he mentioned the same long hadith that has already passed on the authority of Sayyiduna Abu Ayyub al-Ansari (may Allah be pleased with him).
This hadith is mursal, because there is a long gap in time between Umarah bin Ghaziyyah and Sayyiduna Abu Ayyub and Mu'awiyah, whereas the hadith of Sayyiduna Abu Ayyub al-Ansari (may Allah be pleased with him) is connected (muttasil) and fully traced (musnad).