דברי הימים א, פרק כ״ז, פסוק ב׳

The organization of the military forces begins by establishing the leadership for the very first month of the year. The commander appointed to lead this initial division was Jashobeam [מצודת דוד, ביאור שטיינזלץ].

Regarding his background, it is quite possible that Jashobeam the son of Zabdiel is the same individual known as Jashobeam the son of Hachmoni, who was previously recognized as the chief of the mighty men. This connection makes sense, as the majority of the officers selected for these command roles were chosen directly from the elite ranks of David's mighty warriors [רלב״ג].

Under his authority, the total number of troops serving in this first military division stood at twenty-four thousand soldiers [מצודת דוד].