The gate of the inner court facing 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

Ezekiel 46:1-24

This is what the Sovereign Lord says: The gate of the inner court facing 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. The priests are to sacrifice his burnt offering and his fellowship offerings. He is to bow down in worship at the threshold of the gateway and then go out, but the gate will not be shut until evening. 

When the people of the land come before the Lord at the appointed festivals, whoever enters by the north gate to worship is to go out the south gate; and whoever enters by the south gate is to go out the north gate. No one is to return through the gate by which they entered, but each is to go out the opposite gate. 

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.

This is what the Sovereign Lord says: If the prince makes a gift from his inheritance to one of his sons, it will also belong to his descendants; it is to be their property by inheritance. If, however, he makes a gift from his inheritance to one of his servants, the servant may keep it until the year of freedom; then it will revert to the prince. His inheritance belongs to his sons only; it is theirs.

He said to me, “This is the place where the priests are to cook the guilt offering and the sin offering[e] and bake the grain offering, to avoid bringing them into the outer court and consecrating the people.

Around the inside of each of the four courts was a ledge of stone, with places for fire built all around under the ledge. He said to me, “These are the kitchens where those who minister at the temple are to cook the sacrifices of the people.

Why?

In the Temple, every gate and place is arranged for offering and worship, and gates are arranged for princes and people to enter in the different gates. The main principle is to separate from others. The East gate is for the prince, south and north gates are for others. the west side is for the priests' service.

There is regulation in the Temple so our worship has regulation and to the Lord. 

The east gate us open for the Prince only. 

The prince makes a gift from his inheritance to one of his sons will belong to his descendants. But a gift from his inheritance to one of his servants, after the year of freedom will be reverted to the prince.

So the inheritance may be kept to the prince forever.

How?

The word of the Lord can not change or modify. For the Love and the righteousness is in it.