Plead [riyb] my cause, O LORD [Y@hovah], with them that strive [yariyb] with me: fight [lacham]
against them that fight [lacham] against me. KJV-Interlinear
1 A Psalm
LORD, with those who contend with me; fight against those who fight against me!
The word for, plead, is a legal term in which the accused is presenting his case before a judge, in defense of complaints or accusations of another.
The term is a term of a legal process but this is used with a battlefield application, where all enemies are out to kill or capture you and do you no good, therefore the pleading is expressed with urgency, needless to say.
On the battlefield there is no time to wait, the need is now, as patience is not relevant for obvious reasons. However, the principle applies to everyday life as this is the angelic conflict in which we are all caught up.
The fight against those who are fighting with me, is not an excuse to justify ones own beliefs or behavior or personality or agenda, and in so doing using God as a front for whatever purpose you intend.
This is a fight of truth for truth. Meaning that you must be entrenched in truth due to your spiritual growth, in order to make this plea. Otherwise, asking truth to fight for some false representation you may be promoting, will result in no help whatsoever.