C. F. Keil and Franz Delitzsch on Numbers 4:27

Num 4:27

Their service was to be performed “according to the mouth (i.e., according to the appointment) of Aaron and his sons, with regard to all their carrying (all that they were to carry), and all their doing.” - “And ye (the priests) shall appoint to them for attendance (in charge) all their carrying,” i.e., all the things they were to carry. בּמשׁמרת פּקד, to give into keeping. The combination of פּקד with בּ and the accusative of the object is analogous to בּ נתן, to give into a persons’ hand, in Gen 27:17; and there is no satisfactory reason for any such emendations of the text as Knobel proposes.