Bhagavad Gita

ಶ್ರೇಯಾನ್ ಸ್ವಧರ್ಮೋ ವಿಗುಣಃ ಪರಧರ್ಮಾತ್ ಸ್ವನುಷ್ಠಿತಾತ್ ।
ಸ್ವಧರ್ಮೇ ನಿಧನಂ ಶ್ರೇಯಃ ಪರಧರ್ಮೋ ಭಯಾವಹಃ ॥೩೫॥
śreyān svadharmo viguṇaḥ paradharmāt svanuṣṭhitāt |
svadharme nidhanaṃ śreyaḥ paradharmo bhayāvahaḥ ||35||

Gist of the sloka:
Instead of following what is not according to one’s swabhava, imperfection in doing one’s swabhava is superior. Destruction due to following one’s duty is preferable to following another’s, as it’s dangerous.
As previously described every soul has its own swabhava which is unchangeable. One should perform actions which are in alignment with their swabhava. This is their natural karma. One should perform what is in alignment with their swabhava and not otherwise or another’s.
We should build our lives accordingly. If not in alignment with our swabhava, we are trying to overcome something which cannot be changed and it results in conflicts, dissatisfaction, lack of perfection etc., in every action.
It is similar in case of children too. We as parents should closely analyze from their childhood what is the swabhava of the child and appropriately put them in the right environment, courses and profession.
Lord Krishna is very clearly implying that swabhava is with us over multiple births and deaths. Karmas along the lines of swabhava would only enhance our happiness leading to mukthi. If we do karmas not according our swabhava, we are only increasing the path that we need to traverse to reach mukthi and is dangerous.
Here fighting for dharma is Arjuna’s natural swabhava [Both as Indira and as Kuru prince]. Instead if he wants to withdraw from the battle and go into the forest for doing tapas, then it is not only dangerous but against his swabhava. No progress will happen because of it. Lord is instructing him to perform his actions as per karma yoga.