11 And He is called by two names, Jesus Christ; Jesus, because He saves,— Christ, because He is a Priest. And knowing this the inspired Prophet Moses conferred these two titles on two men distinguished above all: his own successor in the government, Auses, he renamed Jesus; and his own brother Aaron he surnamed Christ, that by two well-approved men he might represent at once both the High Priesthood, and the Kingship of the One Jesus Christ who was to come. For Christ is a High Priest like Aaron; since He glorified not Himself to be made a High Priest, but He that spoke unto Him, You are a Priest for ever after the order of Melchizedek. And Jesus the son of Nave was in many things a type of Him.
For when he began to rule over the people, he began from Jordan, whence Christ also, after He was baptized, began to preach the gospel. And the son of Nave appoints twelve to divide the inheritance; and twelve Apostles Jesus sends forth, as heralds of the truth, into all the world. The typical Jesus saved Rahab the harlot when she believed: and the true Jesus says, Behold, the publicans and the harlots go before you into the kingdom of God. With only a shout the walls of Jericho fell down in the time of the type: and because Jesus said, There shall not be left here one stone upon another, the Temple of the Jews opposite to us is fallen, the cause of its fall not being the denunciation but the sin of the transgressors.
Source: Catechetical Lectures (New Advent)