For many in Judah were bound by oath to him, since he was a son-in-law of Shecaniah son of Arah, and his son Jehohanan had married the daughter of Meshullam son of Berechiah.
Many in Judah are bound to Tobiah by oath because of marriage ties linking him to prominent families.
This verse explains why Tobiah’s influence reaches inside Judah.
15So the wall was completed in fifty-two days, on the twenty-fifth of Elul. 16When all our enemies heard about this, all the surrounding nations were afraid and disheartened, for they realized that this task had been accomplished by our God. 17Also in those days, the nobles of Judah sent many letters to Tobiah, and Tobiah’s letters kept coming to them. 18For many in Judah were bound by oath to him, since he was a son-in-law of Shecaniah son of Arah, and his son Jehohanan had married the daughter of Meshullam son of Berechiah. 19Moreover, these nobles kept reporting to me Tobiah’s good deeds, and they relayed my words to him. And Tobiah sent letters to intimidate me.