Hi Missy

Back in the bible days the firstborn son was alive to the inheritance and his siblings dead to it. When asking to bury his father you must understand the father was not dead yet, he was saying let me go and stay with my father until he dies, sort out the inheritance then i will come and follow. Jesus was telling him to follow NOW and let the dead (siblings) dead to the inheritance take care of the father.

hope this answers your question.