ציטירנדיקער פּירוש אויף תהילים 27:3

A kabbalistic approach: When Moses said the words וזאת ליהודה, he addressed the emanation מלכות which is the emanation from which the hereditary dynasty of Yehudah draws its divine input. It is this emanation which gives the kings of Yehudah the power to wage war successfully. Interestingly, David, a king descended from Yehudah, refers to the same emanation as זאת, when he proclaimed in Psalms 27,3: אם תקום עלי מלחמה בזאת אני בוטח, “if war overtakes me, I put my faith in זאת, the emanation from which my forefather Yehudah drew his strength.”
The emanation מלכות, sometimes referred to as זאת, is featured repeatedly in the life of David, such as in Psalms 99,4: ועוז מלך משפט אהב, or in Psalms 72,1: משפטיך למלך תן. This is the reason that David was successful in all his many wars. This is also why he never fails to give thanks to the Lord Who was the source of his success. The whole formula למנצח מזמור לדוד, is evidence that David attributed his success to the מנצח, “The One Who grants victory.” Just because the kings of Yehudah enjoyed the assistance of the attribute/emanation מלכות, it was doubly important for David to acknowledge that ultimately success is rooted in the Original Cause, in Hashem. Seeing that David’s career involved spilling much blood, he was not chosen as the tool to build the Holy Temple which symbolizes peace (Chronicles I 22,8). It was left to his son Solomon, a man of peace, someone who practiced the attribute of צדקה, to build the Temple. This is the meaning of Psalms 72,1 וצדקתך לבן מלך, “and Your clemency to the king’s son.” [David speaking about the status of his son Solomon, contrasting his own dominant characteristic of משפט, with that of his son, i.e. the characteristic צדקה, Ed.]

המחנה האחת והכהו TO THE ONE CAMP AND SMITE IT — The word מחנה is treated grammatically as masculine or feminine: in (Psalms 27:3) “Though a camp should encamp (תחנה) against me” it is feminine; in (Genesis 33:8) “this (הזה) camp” it is masculine. Similarly there are other words treated grammatically as both masculine and feminine. For example, the word שמש in (Genesis 19:23) “The sun was risen (יצא) upon the earth” and in (Psalms 19:7) “His (the sun’s) going forth (מוצאו) is from the end of the heaven”; here it is masculine, but in (2 Kings 3:22) “and the sun shone (זרחה) upon the water” it is feminine. Similarly with רוח: in (Job 1:19) “and behold there came (באה) a great wind” it is feminine, and in the same verse “and smote (ויגע) the four corners of the house” it is masculine; in (1 Kings 19:11) “and a great (גדולה) and strong (וחזק) wind rent (מפרק) the mountains” it is both masculine and feminine. So also in the case of אש: in (Numbers 16:35) “and fire came forth (יצאה) from the Lord” it is feminine, and in (Psalms 104:4) “The flaming (להט) fire” it is masculine.

המחנה האחת, a feminine mode, as occurs also in Psalms 27,3 אם תחנה עלי מחנה, “should an army besiege me.”