“(Also he bade them teach the children of Judah the use of the bow: behold, it is written in the book of Jasher.)”
King James Version (KJV)
1:18 Judah - These he more particularly teacheth, because they were the chief, and now the royal tribe, and likely to be the great bulwark to all Israel against the Philistines, upon whose land they bordered; and withal, to be the most true to him, and to his interest. The bow - That is, of their arms, expressed, under the name of the bow, which then was one of the chief weapons; and for the dextrous use whereof Jonathan is commended in the following song: which may be one reason, why he now gives forth this order, that so they might strive to imitate Jonathan in military skill, and to excel in it, as he did. Jasher - It is more largely and particularly described in the book of Jasher.