Aaron heard God directly placing him in the position of authority (and all his descendants) over the Tent of the Testimony. He alone was to care for the Holy things of God. His mission was clear and no one was to interfere with it at the penalty of death.
His wages would be the bounty from the holy offerings and no permanent inheritance in the land because God was their inheritance. They received the tithes and offerings as provision from God. The holy work was theirs and they would be kept by God.
In many ways we are like Aaron. We as Christians have been given God's Spirit to live in us and we are his holy abode. We are to guard against the unholy things in our lives and live in complete dependence and in fellowship with Him.
We have that still small voice speaking to us and convicting us of wrong and guiding us I the right. We have God's word to speak directly to us and to give us direction and purpose for our days here.
The only purpose we have on earth is to do the work of the Father and increase honor to our Lord Jesus Christ. Since we have this important work to do, no matter where we are assigned (in secular employment, working in Christian mission or in humble service at home) God has a plan and a purpose for us.
Our wages received for our work are established by God. He can always adjust as He sees fit, but when we live within the means God provides we express our affection and contentment in Him. When we live outside our means, we speak to God that His provision is insufficient and we need more than what He offers for our contentment. (By the way, that is a lie from Satan himself spoken in our minds to cause us to stray).
We have no permanent inheritance here in earth. Our inheritance is in Heaven with God himself. We are kept in His care until God's days for us are fulfilled. Our lot is secure and we can know we are doing what God appoints for us of we look to the Bible for our assignments and be faithful in the duties of our day.
May God richly bless you as you seek Him and as you serve Him.