The covenant was sealed by Nehemiah, the priests, Levites, and the leaders over the people (Nehemiah 10). They agreed to observe and do all the commandments, ordinances and statutes of God (V29) and not to intermarry with the people around them. They also agreed to support the service of the house of God (V32-39). They set about repopulating Jerusalem (Nehemiah 11). One-tenth of the people were to live in the city while the other nine-tenths lived in other cities.
During the reign of Darius, records had been kept of the Levites and priests (Nehemiah 12) and Nehemiah brought them all together to celebrate the dedication of the rebuilding (V27). Two large choirs were appointed and these walked in opposite direction on the wall in celebration and praise joining together in the house of the Lord (V37). They offered great sacrifices and rejoiced, for God had made them rejoice with great joy (V43). Appointments were made to keep the storerooms, for singers and gatekeepers, as all Israel gave portions to support the singers, gatekeepers, and others involved in the work of the temple (V44-47).
They read from the Book of Moses and learned that no Ammonite or Moabite should ever come into the Assembly of God because they had hired Balaam to curse them when they came out of Egypt (Nehemiah 13). But Eliashib the priest had aligned himself with Tobiah who was an Ammonite. He had been one of the men who had opposed the rebuilding of the temple and had been given one of the storerooms in the temple complex (V5).
When Nehemiah found this out he had the room cleared out and returned to its intended use (V8-8). He also learned that the Levites had not received their portions so they had returned to working their fields and the work of the temple was affected. Nehemiah contended with the rulers and set them in their place (V11).
The people had ignored the covenant they had made and were doing work and carrying on trade in the Sabbath (V15-16). Nehemiah reminded the nobles of Judah the disaster which came on them was a result of them not keeping the Sabbath (V17-18).
There were others who had married women from Ashdod, Ammon, and Moab, including the son of the high priest Eliashib who was son-in-law to Sanballat, another who had opposed the rebuilding. So Nehemiah drove him away (V23, 28). Nehemiah cleansed them of everything pagan and restored order (V30).