Mann Neeva" and "Matt Uchi"; the words 'neeva' and 'uchi' are opposites. "Neeva" means "low" and "Ucha" means "high". The words "Maan" and "Maat" are related closely to the mind.
This phrase underlines an underlying and highly important concept in Sikhism; the first term "Mann Neeva" literally means "mind low" and highlights the concept of living ones life in humility and in subservience to the Almighty God; a Sikh must discard his or her ego and live a life of humbleness without vanity and snobbishness.
The second term "Matt Uchi" means "morality high"; this second term highlights the concept of living a life which adheres to high moral values and high spiritual principles. So here, the Sikh is asked to live a life of high moral standards with discipline, self-control and virtues endowed; refraining from lowly deeds and keeping away from sinful actions and thoughts.