| Clarke's Commentary on the Bible Hath been chief in this trespass - They who are the first men have been the most capital offenders; so Virgil, Aen. ix. 783: - Unus homo, vestris, o cives, undique septus Aggeribus, tantas strages impune per urbem Ediderit? Juvenum primos tot miserit orco? "Shall one, and he enclosed within your walls, One rash imprisoned warrior, vanquish all? Calm you look on, and see the furious foe Plunge crowds of heroes to the shades below!" Pitt. The first of the Trojan youth were the chief, the most illustrious; so we say the first men of the kingdom for the nobles, etc.
Gill's Exposition of the Entire BibleFor they have taken of their daughters for themselves, and for their sorts,.... Some that were widowers not only took wives to themselves of the above nations, either when they were of Babylon, where many of these nations also were, or rather since their return; but they took for their sons also; yea, some that had wives took Heathenish ones to them, see Malachi 2:13, so that the holy seed; such as the Lord had separated from other nations, chosen them to be an holy people above all others, and devoted them to his service and worship: have mingled themselves with the people of those lands; before mentioned, by marrying with them: yea, the hand of the princes and rulers hath been chief in this trespass; they were the first that went into it, were ringleaders of it, who should by their authority and example have restrained others; or they were in this first trespass (i); which was the first gross and capital one the people fell into after their return from the captivity. (i) "in praevaricatione ista prima", Pagninus, Montanus.
Geneva Study BibleFor they have taken of their daughters for themselves, and for their sons: so that the holy seed have mingled themselves with the people of those lands: yea, the hand of the {b} princes and rulers hath been chief in this trespass. (b) That is, the governors are the chief beginners of it.
Matthew Henry's Concise Commentary9:1-4 Many corruptions lurk out of the view of the most careful rulers. Some of the people disobeyed the express command of God, which forbade all marriages with the heathen, De 7. Disbelief of God's all-sufficiency, is at the bottom of the sorry shifts we make to help ourselves. They exposed themselves and their children to the peril of idolatry, that had ruined their church and nation. Carnal professors may make light of such connexions, and try to explain away the exhortations to be separate; but those who are best acquainted with the word of God, will treat the subject in another manner. They must forebode the worst from such unions. The evils excused, and even pleaded for; by many professors, astonish and cause regret in the true believer. All who profess to be God's people, ought to strengthen those that appear and act against vice and profaneness. | 
