Describe how Joshua was selected as Moses' successor

Moses was asked by God
to go to the mount of Abarim where he would die on account of his rebellion in
the Wilderness of Zin at the water of Meribah. He suggested to God that a
worthy leader be appointed over Israel so that Israel would not be like sheep
without a shepherd. The Lord commanded him to appoint Joshua to succeed him. He
was asked to lay hands on him and cause him to stand before Eleazar the priest,
who would inquire for him by the urim, and all the congregation before whom he
should commission him as a leader. Moses was asked to invest him with some of
his authorities so that the people of Israel would obey him. Moses did according
to the words of God.

Two previous association of Moses and Joshua were: 

• When he
  (Moses) went for the ten commandments on mount Sinai, 
• Joshua was
  one of the twelve spies sent by Moses to spy the land of Canaan.