Psalms 54:5

“He shall reward evil unto mine enemies, etc.] That eyed him as Saul did; that observed his haunts, where he resorted, and who were with him, as the Ziphites did under Saul’s direction; as the Word f712 here used for “enemies” signifies: the mischief they had devised for him, he believed, would be returned upon their own heads; the pit they digged they would fall into themselves; and the net they had spread for others their own feet would be taken in. This was true as of David’s enemies, so of Christ’s, the wicked Jews, who narrowly watched him to take every advantage against him; cut them off in thy truth; root and branch, as Saul, and his family, and his courtiers, quickly were, according…”

“He shall . . . evil--or, "Evil shall return on" (Psa 7:16) my enemies or watchers, that is, to do me evil (Psa 6:7). in thy truth--Thy verified promise.”

“He shall reward evil unto mine enemies - Margin, “those that observe me.” The original word here means literally “to twist, to twist together;” then, to press together; then, to “oppress,” or to treat as an enemy. The reference here is to those who pressed upon him as enemies, or who endeavored to crush him. The idea is that God would recompense them for this conduct, or that he would deal with them as they deserved. Cut them off in thy truth - In thy faithfulness; in thy regard for what is right. This is simply a prayer, or an expression of strong confidence, that God would deal with them as they deserved, or that he would not suffer such conduct to pass without a proper expression of his…”

“Thy truth - Whereby thou art engaged to fulfil thy promises and threatenings. Next: Psalms Chapter 55”

“reward: Psa 31:23, Psa 137:8; Ti2 4:14; Rev 18:6 mine enemies: Heb. those that observe me, Psa 5:8, Psa 27:11 \*marg. cut: Psa 89:49, Psa 143:1, Psa 143:12 Psalms 54:6”