Aaron didn't just decide to step up to the altar. His actions were dictated by a higher authority, a fact Moses emphasized.
Moses' repeated phrase, 'as the LORD commanded,' is more than just a formality; it's the bedrock of legitimate priestly service.
God's Ordained Service
Aaron was the High Priest, but his authority to act stemmed directly from God's commands to Moses. He was called, consecrated, and commissioned. This wasn't a matter of personal initiative but of obedience to divine instruction. God wants His people to worship and serve Him in ways He dictates, not by human invention.
The Unseen Reality Behind the Ritual
This emphasis on command points to the reality that worship and atonement are not merely human activities but divine acts mediated through human obedience. The sacrifices weren't magical; their efficacy was rooted in God's covenant and His decree. This established a pattern: true ministry is always tethered to God's Word and His specific instructions.