A son of Muhammad bin Maslamah (may Allah have mercy on him) and Abdullah bin Abi Bakr bin Hazm (may Allah have mercy on him) related that the division of the wealth of Khaybar was made into eighteen hundred shares, and this was the number of those among the Companions of the Prophet (peace and blessings be upon him) among whom Khaybar was divided, their horsemen and their foot soldiers: the men were fourteen hundred, and the horses were two hundred. So two shares were fixed for the horse, one share for its rider, and one share for each foot soldier.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الفيء والغنيمة / 12871