The verb used here denotes putting something into a state of holiness, that is, to set it apart for sacred purposes (Exodus 40:9–10; Leviticus 8:11–12). Given the gate’s proximity to the temple and its probable primary use as a passage for sacrificial sheep and worshippers, its consecration is understandable. Presumably, this would have involved the use of anointing oil (Exodus 29:35–37).
1 Then Eliashib the high priest rose up with his brothers the priests, and they built the Sheep Gate. They consecrated it and set its doors. They consecrated it as far as the Tower of the Hundred, as far as the Tower of Hananel.