What was the deal with Trump talking about the stage being on ice and it's was built by stupid people? Can't find any pictures or anything on it

Trump mentioned 502 when talking about Beto rally numbers.

https://www.law.cornell.edu/uscode/text/10/502

10 U.S. Code§ 502.Enlistment oath

“I, ____, do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; and that I will obey the orders of the President of the United States and the orders of theofficersappointed over me, according to regulations and the Uniform Code of Military Justice. So help me God.”