Take you; literally, give to you or for you, i.e. yourselves. The selection was to be made by the people themselves. Jethro, in giving Moses the advice on which he thus acted, described the men who were to be selected as "such as fear God, men of truth, hating covetousness" (Exodus 18:21). Moses here describes them rather by qualities, indicating ability and fitness for such a post as that to which they were to be called; they were to be wise; understanding men, men of discernment and sagacity, as well as intelligence; and known among their tribes, men of good repute in the community ("quorum conversatio sit probata," Vulgate; comp. Acts 6:3; 1 Timothy 3:7). And I will make them rulers over you; literally, will set them for your heads, i.e. will appoint them to act as superintendents, managers, and judges over you.
The people approved of the proposal, and acted upon it; and Moses accordingly appointed the persons selected to be chiefs over thousands, and over hundreds, and over fifties, and ever tens (Exodus 18:21); he appointed men also to be officers, that is, persons who should preserve order in the tribes, keeping the registers, acting as scribes, to prescribe and to take account of work, and perhaps also attending to fiscal arrangements ( שֹׁטְרִים, shoterim, a word of general application; cf. Exodus 5:6, Exodus 5:10, Exodus 5:14; Joshua 3:2; 2 Chronicles 26:11, etc. LXX. γραμματεῖς and γραμματο εισαγωγεῖς). In Exodus, Moses is said to have chosen these functionaries (Exodus 18:25); but what many do under the direction of one may be said to be done by him.
In installing the judges, Moses solemnly charged them to deal impartially, fairly, and equitably with those who might come before them.