# served ... which Jehoiada the priest commanded

"did exactly what Jehoiada the priest commanded" 

# Each one took his men ... any of their divisions

The priests and guards served in divisions, with each group working for two weeks. This refers to the point in time when two divisions were present. Thus there were twice as many men as usual.

# were to leave off serving on the Sabbath

"were finishing their work on that Sabbath day"