‘Then Eliashib the high priest rose up with his brothers the priests, and they rebuilt the sheep gate; they sanctified it, and set up its doors; even to the tower of Hammeah they sanctified it, to the tower of Hananel.'
Even the greatest were involved in the project. Eliashib the High Priest (the grandson of Jeshua - Nehemiah 12:10-11), together with his brother priests, set to work with a will on the portion allotted to them. And as each part was built they sanctified it (set it apart to God as holy). The priests were genuinely grateful to God for the fact that the wall was being built, as well they might be, for it protected their Temple. ‘They rose up -- and built.' Thus we see them fulfilling what had been decided on earlier, ‘we will arise and build' (Nehemiah 2:20). The narrative deliberately begins with the activity of the priests, (it does not commence at the north east corner, see Nehemiah 3:32). Central to the whole description is that the house of God is being protected, along with the city that it made holy.
The priests apparently commenced work at the Sheep Gate (near the north east corner), but the work would no doubt also continue on at the same time along the whole of their section on the northern wall, as far as the Tower of Hammeah (The Hundred) and the Tower of Hananel. These may well have been the Towers of the great fortress protecting the northern approach.
‘They rebuilt the Sheep Gate and sanctified it.' This sanctifying of it is prior to the setting up of its doors, which would have occurred some time later (after Nehemiah 6:1). It would be second nature to the priests to sanctify their work as they went along in view of its proximity to the Temple. The Sheep Gate was probably the gate through which sacrificial sheep were brought to the Temple. It was in the north-east corner of the city wall. Compare John 5:2.
They also worked from there westward and rebuilt the Tower of The Hundred, and sanctified it, and as far as the Tower of Hananel. The Tower of The Hundred is not mentioned anywhere else (except in Nehemiah 12:39), but was clearly seen as of importance in relation to the Temple as it was specifically sanctified. (The ‘it' cannot refer to the wall as it is the wrong gender). The Tower of Hananel is mentioned in Nehemiah 12:39, and is referred to as an identifying feature in Jeremiah 31:38 and Zechariah 14:10. It was possibly the northernmost point of Jerusalem.