This is added, either,
1. As a proof of his innocency, which he had now asserted by way of appeal to God. Do thou, O Lord, judge between me and them, whether I be guilty of those rallies and sins which they lay to my charge. And such appeals indeed David useth, Psalms 7:3,4, and elsewhere; but then they are delivered in form of a supposition, and not a positive assertion, as this is. Or rather,
2. As an exception to what he last said. But, O Lord, although I have been innocent to mine enemies, and have given them no cause to hate or persecute me, as they do; yet I must confess I am guilty of many sins and follies against thee, and have given thee just cause to punish me, and to give me up into their hands, and to deny or delay thine help unto me. By foolishness he means sin, as he explains it, which is commonly so called in Scripture; or by his foolishness he means lesser sins, committed through ignorance or inconsiderateness, and by sins those of a grosser nature.