Nehemiah 13:22 - Joseph Benson’s Commentary on the Old and New Testaments

I commanded the Levites that they should cleanse themselves Because the work they now were set upon, though common in its nature, yet was holy in the design of it, and had respect unto the sabbath: and, because the day in which they were to do this was the sabbath day, for the observation whereof they were obliged to purify themselves; that they should come and keep the gates The gates of the city: not daring to trust the common porters, and thinking that the Levites, by virtue of their character, would be more reverenced, and meet with more deference and respect than his domestic servants, he therefore appointed them to this office of keeping the gates on the sabbath, that all traffic might be prevented, and the day not fail to be sanctified, as it ought to be. O my God, spare me according to the greatness of thy mercy By this he intimates, that though he mentioned his good works as things wherewith God was well pleased, and which he had promised to reward, yet he neither did, nor durst, trust to their merit, or his own worthiness, but, when he had done all, he judged himself an unprofitable servant, and one that needed God's infinite mercy to pardon all his sins, and particularly those infirmities and corruptions which adhered to his good deeds.