Ki Teitze תרל”א 1

כי תצא כו’ ונתנו ה”א בידך ושבית שביו.
When you go.out to battle your enemy and HaShem your G-d will give him into your hand and you will capture and captive.
This pasuk can also be referring to the internal battle that a person has with his yetzer hara
כי בכל דבר יש נקודה חיות מהש”י רק שנסתר ונעלם וצריך מלחמה ועבודה כל ימות החול למצוא זאת הנקודה
In everything there is a life force from HaShem, just that it’s hidden and covered, and it requires a battle and hard work of the days of the week to find this point
אח”כ נעשה שבת שמתגלה כי הש”י מחי’ הכל
Then afterwards one reaches a stage of Shabbos where it becomes revealed that HaShem is sustaining everything
שזה ענין ש”ק שבנ”י מעידין על בריאת שמים וארץ שגם עתה קיומם רק בעשרה מאמרות.
This is the idea of Shabbos that Bnei Yisrael testify to the creation of the world that even now their existence is only because of the Ten Sayings (that HaShem created the world with)
ובחול צריכין מלחמה ע”ז.
However during the weekdays it requires a battle for this.
ומ”מ גם השבת בא כפי הטירחה והעבודה בחול כמ”ש מי שטרח בע”ש יאכל בשבת.
Nevertheless even the (revelation) that one receives on Shabbos comes in proportion to the amount of effort and work that one put in in the weekday. As it says one who toiled on erev Shabbos will eat on Shabbos
וערב שבת הוא התערובות שיש מבחי’ שבת גם בחול
Erev Shabbos is the mixture that there is from the concept of Shabbos in the weekday. (When one can tap into the holiness of Shabbos also during the weekday).
כמ”ש בדברו מעריב ערבים
As it says with his words he creates darkness. This can also mean that HaShem mixes (מעריב) His word (דברו) even in the darkness (ערבים)

וצריך האדם לידע כי גם הגבורה נגד היצה”ר רק בכח הש”י כדכ’ ונתנו ה”א בידך
One needs to realise and know that even the strength that he has over the yetzer hara, is only due to hashem. As it says, He will give him (your enemy) into your hand.
פי’ אף שהי’ ע”י כח התגברות האדם כדכ’ בידך שהוא ע”ש הכח.
Meaning that even though the
enemy is given ‘into your hand’ which shows that you triumphed because of hard work and correct choice.
ועכ”ז הש”י כל יכול והוא מסייע לאדם שיהי’ בדרך כחו אף שהוא מהש”י
Nevertheless HaShem is all encompassing and He helps the person in such a way that it appears that it is due to his choices, however it is all from HaShem.
כמ”ש ולך ה’ החסד כו’ כמעשהו.
We see this idea in the passuk: ‘to You is kindness, for You give to each one according to their actions’.
ומקשין מה החסד. אך אדרבא אף שהכל מהש”י מ”מ נותן לאדם באופן שיהי’ מן האדם עצמו.
And the question is asked, if one is rewarded according to his actions, so why is it a kindness on HaShem’s behalf to bestow him accordingly? However the answer is that it is actually the other way around. Everything is really from HaShem and due to Him, however He gives man an opportunity to feel as if he has earned it.
ושבית שביו כשיודעין זה שהוא מהש”י.
And you will capture a captive, when one gets back the thing that the yetzer Hara took from him and captured it back. This only happens when one realises that it is all from HaShem.

והכלל כי בכל מעשה טוב ומצוה יש ענין המעשה והחזרת הדבר להשי”ת.
The rule is that in every good action and mitzvah, there is the action and then afterwards returning that very thing to HaShem. (acknowledging that it is all from HaShem, even the triumph).
כי אף שיטריח האדם ויעשה נפלאות אם לא יחזר המצוה להש”י לא עשה כלום כי לא החזיר את השליחות לבעליו.
For even if one works very hard and does amazing things, nevertheless if he doesn’t return the mitzvah to HaShem, he hasn’t yet done anything, for he hasn’t completed his mission. The mission will only be complete when he returns the mission to HaShem.
והחזרה לא יוכל להיות רק עי”ז שיודע שהכל מהש”י.
And Returning the mission can only take place when one realises that everything is from HaShem.
[וז”ש מי שדעתו שפלה כו’] וזה ושבית שביו. שיחזיר הנקודה אליו ית’ ע”י שיודע שהוא רק ממנו ית’:
This is what is meant by capturing a captive. When he returns that very point to HaShem, which is the realization that everything (even the triumph) is only because of HaShem.