Mishkat al-Masabih 1708

Ja'far b. Muhammad told in mursal form on his father’s authority that the Prophet (ﷺ) cast three handfuls of earth on the dead with both hands, that he sprinkled water on his son Ibrahim’s grave, and that he put small pebbles on it. It is transmitted in Sharh as-sunna, and Shafi’i transmitted from “he sprinkled".