Ps 54:2

“"I have been made sad in my exercise, and have been troubled" [Psalm 55:2]. Where made sad, where troubled? "In my exercise," he says. Of evil men, whom he suffers, he has made mention, and the same suffering of evil men he has called his "exercise." Think ye not that without profit there are evil men in this world, and that no good God makes of them. Every evil man either on this account lives that he may be corrected, or on this account lives that through him a good man may be exercised. O that therefore they that do now exercise us would be converted, and together with us be exercised! Nevertheless, so long as they are such as to exercise, let us not hate them: because in that wherein any one of them is evil, whether unto the end he is to persevere, we know not; and ofttimes when to yourself you seem to have been hating an enemy, you have been hating a brother, and know not. The devil and his angels in the holy Scriptures have been manifested to us, that for fire everlasting they have been destined. Of them only must amendment be despaired of....Therefore since this rule of Love for you is fixed, that imitating the Father you should love an enemy: for, He says, "love your enemies:" [Luke 6:27] in this precept how would you be exercised, if you had no enemy to suffer? You see then that he profits you somewhat: and let God sparing evil men profit you, so that thou show mercy: because perchance thou too, if you are a good man, out of an evil man hast been made a good man: and if God spared not evil men, not even you would be found to return thanks. May He therefore spare others, that has spared you also. For it were not right, when you had passed through, to close up the way of godliness.”

“"Attend to me and hear me." Here is described the order by which God accepts prayer: namely, when he accepts the prayer or petition, because the petitioner is not accepted through the prayer, but the prayer of those to be accepted is accepted through the petition. Hence it is said in Gen. 4: "The Lord looked first to Abel and then to his offerings." "Attend to me," that is, accept me. Or "attend to my affliction." Exod. 3: "Seeing, I have seen the affliction of my people." "And hear me." Ps. (63): "Hear, O God, my prayer, when I make supplication."”

“"I was saddened." Here he explains the tribulations. And first he sets forth the cause of the tribulation. Second, its severity. Third, the remedy. The cause of the tribulation was the suffering he was enduring. This also applies to Christ: "My soul is sorrowful even unto death." This tribulation of Christ can be considered with respect to its fruit, its manner, and its motive. The fruit of the tribulation of the saints is the exercise for justice, as in military training. And therefore he says, "in my exercise," that is, in the tribulation which you send for the sake of training, "I was saddened." But against this, Prov. 12: "Nothing that befalls the just man will sadden him." It must be said that the just man is not saddened by the sorrow of this world, which brings death, but by the sorrow of repentance, which is according to God. Or it must be said that there is one kind of sorrow that is a passion, and this bodily imitates suffering; and this does not befall the wise man. There is another sorrow that is called a pre-passion, which is a sudden movement; and this sorrow was in Christ. And there is a twofold exercise for justice. One is undertaken voluntarily: 1 Tim. 4: "Exercise yourself." The other exercise is imposed from outside, as is the case here. The manner of tribulation is twofold. One is by words, namely by threatening. The other is when tribulation is inflicted by deeds, by persecuting. Regarding the first, he says, "I was disturbed by the voice of the enemy." One is disturbed when the tranquility of the heart is entirely removed -- "by the voice of the enemy" who threatens and blasphemes. Jer. 12: "My inheritance has become to me like a lion in the forest." Regarding the second, he says, "by the tribulation of the sinner," namely inflicted upon me. Ps. (118): "Many are those who persecute me." The cause of this tribulation is twofold. Sometimes they afflict out of deliberate malice; sometimes out of passion. Regarding the first, he says, "because they turned their iniquities upon me," that is, they carried out against me the iniquity they had planned to perpetrate. Regarding the second, he says, "and in anger they were troublesome to me." Gen. 49: "Cursed be their fury."”