ASK

Then the leaders of the tribe of Levi came to consult with Eleazar the priest, Joshua son of Nun, and the leaders of the other tribes of Israel. They came to them at Shiloh in the land of Canaan and said, “The lord commanded Moses to give us towns to live in and pasturelands for our livestock.” So by the command of the lord the people of Israel gave the Levites the following towns and pasturelands out of their own grants of land. (Joshua 21:1-3) 

Despite the Lord's command that lands should be given to the tribe of Levy, they have the responsibility of asking again and reminding the leaders of what God had instructed. God made many promises to us, but we need to ask and remind Him of them. You should realize that God never forgets, asking indicates our trust in Him and His ability to fulfill His promises. 

The last verse of the chapter says ‘Not a single one of all the good promises the Lord had given to the family of Israel was left unfulfilled; everything he had spoken came true’. (Joshua 21:45).

He has the power to accomplish anything, as there are no impossibilities with Him. The Scripture instructs us to ask until our joy is fully satiated (John 16:14). Never give up, always keep asking and believing.