The Levites thirty years of age or older were counted, and the total number of men was 38,000.
Here we have, I. The crown entailed, according to the divine appointment, Ch1 23:1. David made Solomon king, not to reign with him, or reign under him, but only to reign after him. This he did, 1. When he was old and full of days. He was but seventy years old when he died, and yet he was full of days, satur dierum - satisfied with living in this world.
Commenting on 1 Chronicles 23:1-23
Now the Levites were numbered from the age of thirty years, and upward,.... So they were numbered in the days of Moses, and by his order, and so they were now at first; though afterwards there was a new reckoning of them, Ch1 23:24.
the Levites were numbered . . . thirty and eight thousand--Four times their number at the early census taken by Moses (see on Num. 4:1-49; Num. 26:1-51). It was, in all likelihood, this vast increase that suggested and rendered expedient that classification, made in the last year of David's reign, which the present and three subsequent chapters describe. by their polls, man by man--Women and children were not included.