Jamieson, Fausset and Brown on Nehemiah 12:47

47. all Israel ... sanctified holy things unto the Levites,--&c. The people, selecting the tithes and first-fruits, devoted them to the use of the Levites, to whom they belonged by appointment of the law. The Levites acted in the same way with the tithes due from them to the priests. Thus all classes of the people displayed a conscientious fidelity in paying the dues to the temple and the servants of God who were appointed to minister in it.