For the use of “thousand” as equivalent to “family,” see 1 Samuel 23:23; Judges 6:15 margin. In Numbers 1:16 it may mean whole tribes.
Related Commentaries of 1 Samuel 10:19
1 Samuel 10:19
19 And ye have this day rejected your God, who himself saved you out of all your adversities and your tribulations; and ye have said unto him, Nay, but set a king over us. Now therefore present yourselves before the LORD by your tribes, and by your thousands.