Leviticus 1:9 gives the same instruction for washing inwards and legs in the burnt offering ritual.

Leviticus 1:13 similarly prescribes washing inwards and legs for a sheep or goat burnt offering.

Leviticus 8:21 records Moses executing this exact command during Aaron's ordination.

Leviticus 9:14 describes Aaron washing the inwards and legs for his own burnt offering, following the same procedure.

Leviticus 1:8 describes placing the pieces on the altar, a subsequent step to the washing and cutting here.