A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
est 10:1AHASUERUS' GREATNESS. MORDECAI'S ADVANCEMENT. (Est 10:1-3)
Ahasuerus laid a tribute--This passage being an appendix to the history, and improperly separated from the preceding chapter, it might be that the occasion of levying this new impost arose out of the commotions raised by Haman's conspiracy. Neither the nature nor the amount of the tax has been recorded; only it was not a local tribute, but one exacted from all parts of his vast empire.
est 10:2the declaration of the greatness of Mordecai--The experience of this pious and excellent Jew verified the statement, "he that humbleth himself shall be exalted" [Mat 23:12; Luk 14:11; Luk 18:14]. From sitting contentedly at the king's gate, he was raised to the dignity of highest subject, the powerful ruler of the kingdom. Acting uniformly on the great principles of truth and righteousness, his greatness rested on a firm foundation. His faith was openly avowed, and his influence as a professor of the true religion was of the greatest usefulness for promoting the welfare of the Jewish people, as well as for advancing the glory of God.
est 10:3For Mordecai . . . was next unto King Ahasuerus . . . great among the Jews, &c.--The elevation of this pious and patriotic Jew to the possession of the highest official power was of very great importance to the suffering church at that period; for it enabled him, who all along possessed the disposition, now to direct the royal influence and authority in promoting the interests and extending the privileges of his exiled countrymen. Viewed in this light, the providence of God is plainly traceable in all the steps that led to his unexpected advancement. This providential interposition is all the more remarkable, that, as in the analogous case of Joseph, it was displayed in making the ordinary and natural course of things lead to the most marvellous results. To use the pious words of an eminent prelate, "though in the whole of this episode there was no extraordinary manifestation of God's power, no particular cause or agent that was in its working advanced above the ordinary pitch of nature, yet the contrivance, and suiting these ordinary agents appointed by God, is in itself more admirable than if the same end had been effected by means that were truly miraculous." The sudden advancement of individuals from obscurity and neglect to the highest stations of power and influence is, in Eastern courts, no extraordinary nor infrequent occurrence. The caprice, the weak partiality of the reigning sovereign, or, it may be, his penetrating discernment in discovering latent energy and talent, has often "raised the beggar from the dunghill, and set him among princes" [Sa1 2:8]. Some of the all-powerful viziers in modern Persia, and not a few of the beys in Egypt, have been elevated to their respective dignities in this manner. And, therefore, the advancement of "Mordecai, who was next unto Ahasuerus, and great among the Jews," was in perfect accordance with the rapid revolution of "the wheel of fortune" in that part of the world. But, considering all the circumstances of Mordecai's advancement, not only his gaining the favor of the king, but his being "accepted of the multitude of his brethren, it was beyond all controversy the doing of the Lord, and was truly marvellous in his people's eyes."
accepted of the multitude of his brethren--Far from being envious of his grandeur, they blessed God for the elevation to official power of so good a man.
speaking peace to all his seed--While his administration was conducted with a mild and impartial hand, he showed a peculiarly warm and friendly feeling to all his countrymen when asked his counsel or his aid.