In Numbers 12, Miriam and Aaron were critical of Moses over his marriage.  Then in anger, they spiritualized their attack.  Miram and Aaron said, “Has the Lord indeed spoken only through Moses? Has He not spoken through us also?” (v. 2). True, He had at times spoken through both of them, but now they have become prideful.  This stands in vivid contrast to Moses who was more humble and meek “than anyone on the face of the earth” (v. 3).  So God called them to account for trying, in pride, to put themselves and their occasional words from the Lord, on the same level as the greater prophet Moses. (It is noteworthy that Moses did not react in anger or defend himself.)  The proud Miriam, the likely initiator of the critical speech, was stricken with leprosy; she was only saved by the prayers of the meek and humble Moses (vs 10-13).   Humility is a big thing with God. 

“Those who wait for the Lord and are humble, they will inherit the land.” (Psalm 37:9-11) Jesus said, “Blessed are the meek: for they shall inherit the earth” (Matthew 5:5).