His boss 'assured' him that he had her continued support. = His boss 'assured' him of her continued support. = “You have my continued support,” his boss 'assured' him.
You can 'rest assured' [=you can be sure] that these mistakes won't happen again. = 'Rest assured', these mistakes won't happen again.
They are not 'assured of' being paid. [=it is not certain that they will be paid]
(..) If you're picked up buying a $ sports car in Newport Beach... ...l'll be disappointed. I want my people to find you, and when they do... ...rest assured, we won't hand you over to the police. So, my advice to you again is this: run and hide. That is all that I ask. Mr. Benedict, our guys say that (..)2001 Ocean's Eleven