If I rejoiced - I did not avenge myself on my enemy; and I neither bore malice nor hatred to him.
If I rejoiced at the destruction of him that hated me - Job here introduces another class of offences, of which he says he was innocent. The subject referred to is the proper treatment of those who injure us. In respect to this, he says that he was entirely conscious of freedom from exultation when calamity came upon a foe, and that he had never even wished him evil in his heart. The word “destruction” here, means calamity, disappointment, or affliction of any kind. It had never been pleasant to him to see one who hated him suffer. It is needless to remark how entirely this accords with the New Testament. And it is pleasant to find such a sentiment as this expressed in the early age of the world, and to see how the influence of true religion is at all times the same. The religion of Job led him to act out the beautiful sentiment afterward embodied in the instructions of the Savior, and made binding on all his followers; Matthew 5:44. True religion will lead a man to act out what is embodied in its precepts, whether they are expressed in formal language or not.
Or lifted up myself - Been elated or rejoiced.
When evil found him - When calamity overtook him.