C. F. Keil and Franz Delitzsch on Nehemiah 12:27

Neh 12:27

At the dedication (i.e., at the time of, בּ denoting nearness of time) they sought the Levites out of all their places, to bring them to Jerusalem to keep the dedication. Only a portion of the Levites dwelt in Jerusalem (Neh 11:15-18); the rest dwelt in places in the neighbourhood, as is more expressly stated in Neh 12:28 and Neh 12:29. ושׂמחה, to keep the dedication and joy, is not suitable, chiefly on account of the following וּבתודות, and with songs of praise. We must either read בּשׂמחה, dedication with joy (comp. Ezr 6:16), or expunge, with the lxx and Vulgate, the ו before בּתודות. בּ must be repeated before מצלתּים from the preceding words. On the subject, comp. 1Ch 13:8; 1Ch 15:16, and elsewhere.