Komentarz do Kapłańska 9:5

ויקתו את אשר צוה משה, They took what Moses had commanded, etc. When the Torah writes "which Moses had commanded," the Torah means what Moses had commanded to Aaron, i.e. that Aaron took the animals Moses had commanded him to take and sacrifice on behalf of the people. Had the Torah only written that the people took the animals Aaron had commanded them to take, I would not have known of Aaron's involvement, i.e. that Aaron carried out Moses' instructions. Furthermore, perhaps the Torah wrote "which Moses commanded" as a contrast to the usual "as G'd had commanded," that Moses' command sufficed for the people to carry out these orders although they had not been assured that the command which they were bidden to carry out had emanated from G'd.

And the entire congregation approached. Every place that the Torah mentions ‘approaching’ it implies becoming closer than usual. Toras Kohanim interprets this way as well: “They all approached in rejoicing.” It might be also possible to say that the verse is teaching us what is mentioned in Berachos (6b) that when one is going to a Beis Knesses there is a mitzvah to run.