Bhagavad Gita

ಗಾಂಡೀವಂ ಸ್ರಂಸತೇ ಹಸ್ತಾತ್ ತ್ವಕ್ ಚೈವ ಪರಿದಹ್ಯತೇ ।
ನಚ ಶಕ್ನೋಮ್ಯವಸ್ಥಾತುಂ ಭ್ರಮತೀವ ಚ ಮೇ ಮನಃ ॥೩೦॥
gāṃḍīvaṃ sraṃsate hastāt tvak caiva paridahyate |
naca śaknomyavasthātuṃ bhramatīva ca me manaḥ ||30||

Sloka 1:30
Gist of the sloka:
Gandhiva [might bow of Arjuna] is slipping from my hands; my skin is burning; unable to stand and my mind is confused.
Arjuna is describing the effect the emotions is having on his physical body. Due to fear the palms is sweating and he is unable to hold on to his mighty bow Gandhiva. His skin due to anxiety is showing burning sensation and he is unable to stand firmly in the chariot. All of these is the physical symptoms of the state of his mind – which highly disturbed.
The mind and physical body are interlinked. When the mind is disturbed, the body cannot be still. You can see it when a person who is disturbed cannot sit still but gets up and walks around until he reaches a state of calmness. Similar is the case when a person is calm, he is able to sit still.
Hence the recommendation that before meditating that one sit still, do pranayama to still the breath [inner prana kosha/body] and there by calming the mind. All these required to enhance and concentrate the mind on Lord – also known as Dhyana yoga.