Jamieson, Fausset and Brown on Nehemiah 8:17

17. since the days of Jeshua ... had not the children of Israel done so--This national feast had not been neglected for so protracted a period. Besides that it is impossible that such a flagrant disregard of the law could have been tolerated by Samuel, David, and other pious rulers, its observance is sufficiently indicated (1Ki 8:2, 65; 2Ch 7:9) and expressly recorded (Ezr 3:4). But the meaning is, that the popular feelings had never been raised to such a height of enthusiastic joy since the time of their entrance into Canaan, as now on their return after a long and painful captivity.