Though Tobiah is called "the servant" or "slave" Nehemiah 2:10, Nehemiah 2:19, and was perhaps a bought slave of Sanballat's, yet he was in such a position that Jewish nobles readily contracted affinity with him. This is quite in harmony with the practice of the East, where slaves often fill high positions and make great marriages.

He was the son-in-law of Shechaniah - Previously to the coming of Nehemiah, the Jews seemed to be fast intermixing with the heathen, by intermarriages with Ashdodites, Ammonites, and Moabites; see Nehemiah 13:23. Ezra had many evils of this kind to redress, (Ezra 9:3, etc.), chiefly among the common people, though there were both chiefs and priests in that trespass. But here we find the heathen and Jewish nobles interlinked; and the latter were so far imbued with the spirit of idolatry, that they forgot God, his service, their brethren, and their own souls.

For there were many in Judah sworn unto him,.... To Tobiah, who not only in a private manner corresponded with him by letters, but bound themselves by an oath to him to be true to his interest, and do as he should advise them:

because he was the son in law of Shechaniah, the son of Arah; of a family that came up with Zerubbabel from the captivity, Ezra 2:5 and very probably of considerable note:

and his son Johanan had taken the daughter of Meshullam the son of Berechiah; a very eminent person, concerned in building the wall, Nehemiah 3:4.

For many in Judah were sworn unto him, for he was the son-in-law of Shecaniah the son of Arah; and his son Johanan had taken (to wife) the daughter of Meshullam the son of Berechiah. In this case Tobiah was connected with two Jewish families, - a statement which is made to confirm the fact that many in Judah were שׁבוּעה בּעלי, associates of an oath, joined to him by an oath, not allies in consequence of a treaty sworn to (Bertheau). From this reason being given, we may conclude his affinity by marriage was confirmed by an oath. Shecaniah ben Arah was certainly a respectable Jew of the race of Arah, Ezra 2:5. Meshullam ben Berechiah appears among those who shared in the work of building, Nehemiah 3:4 and Nehemiah 3:30. According to Nehemiah 13:4, the high priest Eliashib was also related to Tobiah. From the fact that both Tobiah and his son Jehohanan have genuine Jewish names, Bertheau rightly infers that they were probably descended from Israelites of the northern kingdom of the ten tribes. With this the designation of Tobiah as "the Ammonite" may be harmonized by the supposition that his more recent or remote ancestors were naturalized Ammonites.

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.

6:15-19 The wall was begun and finished in fifty-two days, though they rested on the sabbaths. A great deal of work may be done in a little time, if we set about it in earnest, and keep close to it. See the mischief of marrying with strangers. When men once became akin to Tobiah, they soon became sworn to him. A sinful love leads to a sinful league. The enemy of souls employs many instruments, and forms many projects, to bring reproach on the active servants of God, or to take them from their work. But we should follow the example of Him who laid down his life for the sheep. Those that simply cleave to the Lord and his work will be supported.