Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: The Prophet (peace and blessings be upon him) said: "On Tuesday Surah al-Hadid was revealed; on Tuesday Allah Almighty created iron; on Tuesday the son of Sayyiduna Adam (peace be upon him) killed his brother." (The narrator says:) So the Prophet (peace and blessings be upon him) forbade cupping on Tuesday.
Al-Tabarani recorded it; its chain contains a narrator, Maslamah bin Ali al-Khushani, and he is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الطب / 8331