This is a Navajo saying that means “it’s up to you” or “you decide what will happen/be done”. “You decide if you’ll learn.” “You decide how long to water the grass.” etc.
Generally, this is a way of way of making someone responsible for their own actions, and is a prevalent feature in a family unit.
Táá hó’ájit’éégóó is another way of saying this. You’re most likely to hear this being used from parent to a child, or a leader to the people he serves, or in most cases where a person is being encouraged to make well-rounded decisions.
Note: níláh, in the midst of frustration or irritation, can mean “get away!” or “leave me alone” – you’ll have to take into account the high tones and the context