Kohathites

the descendants of Kohath. They formed the first of the three divisions of the Levites (Ex 6:16; 6:18; Num 3:17). In the journeyings of the Israelites they had the charge of the most holy portion of the vessels of the tabernacle, including the ark (Num 4:1etc.). Their place in the marching and encampment was south of the tabernacle (Num 3:29; 3:31). Their numbers at different times are specified (Num 3:28; 4:36; 26:57; 26:62). Samuel was of this division.

EBD - Easton's Bible Dictionary