Mujammi' b. Jariya said

Khaibar was divided among those who had been at al-Hudaibiya, and Allah's Messenger ﷺ divided it into eighteen portions. The army was one thousand five hundred of which three hundred were cavalry, and he gave two shares to a horseman and one to a footman. Abu Dawud transmitted it, saying Ibn ‘Umar’s tradition1 is sounder, and it is the one which is followed. The error in the tradition of Mujammi’ was because he said three hundred horsemen when there were only two hundred. Habib b. Maslama al-Fihri said he saw the Prophet (ﷺ) give a quarter of the spoil on the outward journey and a third on the return journey.2 1. I have available two editions of Abu Dawud’s Sunan (Cairo, 1280 and 1348 A .H.). Both give Ibn Mu'awiya in place of Ibn 'Umar. See Jihad, 144. 2. This tradition and the following one are explained as referring to a section of the army which comes in contact with the enemy. The greater amount granted them when this happens on the return journey is because there is more difficulty and danger in fighting after having gone through the campaign. The second tradition is more explicit by making it clear that the fifth was deducted. Abu Dawud transmitted it.