No one is to return through the gate by which they entered

Ezekiel 46:1-24
The gate of the inner courtfacing east is to be shut on the six working days, but on the Sabbath day and on the day of the New Moon it is to be opened.  The prince is to enter from the outside through the portico of the gateway and stand by the gatepost. but the gate will not be shut until evening. 
No one is to return through the gate by which they entered.
 At the feasts and the appointed festivals, when the prince provides a freewill offering to the Lord—whether a burnt offering or fellowship offerings—the gate facing east is to be opened for him. He shall offer his burnt offering or his fellowship offerings as he does on the Sabbath day. Then he shall go out, and after he has gone out, the gate will be shut.
The prince must not take any of the inheritance of the people, driving them off their property. He is to give his sons their inheritance out of his own property, so that not one of my people will be separated from their property.
Why?
East gate is open for prince come to provide offering. On Sabbath day it is open whole day, but on festivals gate will be shut when prince go out.
Each manner inside Temple have rules and regulations. People get in from north have to go out from south gate, he must leave from opposite side.
The Eastern Gate of Jerusalem is also called the Golden Gate or the Beautiful Gate (Acts 3:2). In Hebrew, it is Sha'ar Harahamim, the “Gate of Mercy.” When Jesus entered Jerusalem from the Mount of Olives in Matthew 21, He used a gate in the same location as the current Eastern or Golden Gate.
It is also symbolic that we are to follow  the whole God's word without any hint of returning.
How?
There is not way to return to follow God's way. God's word is our way of blessing.