Musnad Abi Ya'la 2643 — he said: I saw the blessed head of Sayyiduna

It is narrated from Abd al-Malik bin Umayr (may Allah have mercy on him) that he said: "I saw the blessed head of Sayyiduna al-Husayn bin Ali (may Allah be pleased with him) brought to Ubaydullah bin Ziyad; then I saw the head of Ubaydullah bin Ziyad brought to al-Mukhtar bin Abi Ubayd; then I saw the head of al-Mukhtar brought to Mus'ab bin al-Zubayr (may Allah have mercy on him); and then I saw the head of Mus'ab (may Allah have mercy on him) presented before Abd al-Malik bin Marwan (may Allah have mercy on him)."
Imam Abu Ya'la (may Allah have mercy on him) said (commenting on these events): "It is as though these people had no other business except heads (exchanging and displaying them)!"