Rashi on TanakhPsalms 54

and with Your might, avenge me Heb. תדינני, Wreak my vengeance, as (Deut. 32:36): “When the Lord will avenge (ידין) His people.”

to those who lie in wait for me Heb. לשררי, those who eye me, an expression of (Num. 24:17): “I see him (אשורנו), but not near.”

with Your truth Since You are truthful, and You said that You would wreak vengeance upon talebearers and those who pursue to kill, therefore, cut them off.