Nehemiah 6:18
For there were many in Judah sworn unto him, because he was the son in law of Shechaniah the son of Arah; and his son Johanan had taken the daughter of Meshullam the son of Berechiah. For there were many in Judah sworn unto him, because he was the son in law of Shechaniah the son of Arah; and his son Johanan had taken the daughter of Meshullam the son of Berechiah.
Many in Judah were bound to Tobiah by sworn allegiance rooted in personal and family ties of marriage. Tobiah was the son-in-law of Shechaniah the son of Arah, and his son Johanan had taken in marriage the daughter of Meshullam the son of Berechiah. These marriage connections joined his family to theirs and to Shechaniah's family.
These family ties explain the influence and support Tobiah held among the people. They placed influential Jews in a position to support Nehemiah's adversary and to help undermine the wall-building work.
The ties linked members of Judah with God's enemies and became a snare to them. Those involved were not wholehearted in serving God, and the relationships drew them into secret cooperation with an enemy of God's work. Those so bound were willing to betray their pledged support, disclosing Nehemiah's plans to Tobiah and thereby weakening the work of rebuilding.