Miriam was driven by jealousy!
Jealousy causes one to put down another's rise, in order to safe guard one's own self importance. King Herod put down babies in order to remain King. Joseph's brothers tried to destroy Joseph from being their head.
Jealous people cannot stand the rise of another, especially one whom they consider inferior. Jealous people cannot stand not being number one. It has to be them or they will castigate the one that becomes number one.
This is the spirit that led Lucifer to want to compete with God. He could not stand God having and taking all the glory. This is the more reason why we must guard against bitter jealousy.
WHAT IS NEXT?