Al-Sha'bi (may Allah have mercy on him) narrated: Sayyiduna Ali (may Allah be pleased with him) led the funeral prayer over Sayyiduna Ammar bin Yasir and Hashim bin Utbah (may Allah be pleased with them both) on the day of the Battle of Siffin. Of the two, Ammar (may Allah be pleased with him) was nearer to Ali (may Allah be pleased with him), and of the two, Hashim (may Allah be pleased with him) was nearer to the qiblah.
Hadith Referenceالمعجم الكبير للطبراني / باب الهاء / 18653