I rejoice at your word, as one that finds great spoil.
Read Chapter 119
Augustine of Hippo
AD 430
160. Then follows, "I am as glad of Thy word as one that findeth great spoils" (ver. 162). By the same words he conquered, of which he stood in awe. For spoils are stripped from the conquered; as he was overcome and despoiled of whom it is said in the Gospel, "except he first bind the strong man." But many spoils were found, when, admiring the endurance of the Martyrs, even the persecutors believed; and they who had plotted to injure our King by the injury of His soldiers, were gained over by Him in addition. Whoever therefore standeth in awe of the words of God, fearing lest he be overcome in the contest, rejoiceth as conqueror in the same words.
Spoil. Having just mentioned fear; lest any should think that he entertained any secret dislike for the law; he adds, that it gives him more content than the greatest treasures or conquests can the miser or the hero, ver. 14, 72, and 127. (Calmet)
He rejoiceth thus in keeping the commandments, how difficult soever they may be. (Worthington)