15 and that they should publish and proclaim in all their towns and in Jerusalem, "Go out to the hills and bring branches of olive, wild olive, myrtle, palm, and other leafy trees to make booths, as it is written." 16 So the people went out and brought them and made booths for themselves, each on his roof, and in their courts and in the courts of the house of God, and in the square at the Water Gate and in the square at the Gate of E'phraim. 17 And all the assembly of those who had returned from the captivity made booths and dwelt in the booths; for from the days of Jeshua the son of Nun to that day the people of Israel had not done so. And there was very great rejoicing.
Matthew Henry's Commentary on Nehemiah 8:15-17
Commentary on Nehemiah 8:13-18
(Read Nehemiah 8:13-18)
They found written in the law about the feast of tabernacles. Those who diligently search the Scriptures, find things written there which they have forgotten. This feast of tabernacles was a representation of the believer's tabernacle state in this world, and a type of the holy joy of the gospel church. The conversion of the nations to the faith of Christ, is foretold under the figure of this feast, Zechariah 14:16. True religion will render us strangers and pilgrims upon earth. We read and hear the word acceptably and profitably, when we do according to what is written therein; when what appears to be our duty is revived, after it has been neglected. They minded the substance; else the ceremony had been of no use. They did it, rejoicing in God and his goodness. These are the means which the Spirit of God crowns with success, in bringing the hearts of sinners to tremble and to become humbled before God. But those are enemies to their own growth in holiness, who always indulge sorrow, even for sin, and put away from them the consolations tendered by the word and Spirit of God.