Amr, or Safwan bin Abdullah bin Safwan (may Allah have mercy on him), said: I saw Ibn Abbas (may Allah be pleased with them both) pray two rak'ahs on top of Zamzam during the solar eclipse, bowing twice in each rak'ah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الخسوف / 6375