What does Ezekiel 44:5 mean?

The Lord said to me, 'Son of man, pay close attention. Look carefully and listen closely to everything I tell you about all the regulations and instructions for the Lord’s temple. Pay attention to who can enter the temple and who must stay out. Ezekiel 44:5 - Modern Text Bible

(God urges Ezekiel to be alert and attentive, because the details about the temple’s rules and who may enter are crucial.)