Bhagavad Gita

ಪ್ರಸಾದೇ ಸರ್ವದುಃಖಾನಾಂ ಹಾನಿರಸ್ಯೋಪಜಾಯತೇ ।
ಪ್ರಸನ್ನಚೇತಸೋ ಹ್ಯಾಶು ಬುದ್ಧಿಃ ಪರ್ಯವತಿಷ್ಠತಿ ॥೬೫॥
prasāde sarvaduḥkhānāṃ hānirasyopajāyate |
prasannacetaso hyāśu buddhiḥ paryavatiṣṭhati ||65||

Gist of the sloka:
Once the mind is like clear water, the seekers loses all his fears, as such, a mind will only seek Lord and remains there.
If the mind has impurities, the world appears to be full of impurities. All problems are due to this situation. If we do not concentrate our mind, all actions are fruitless. Keeping the mind clean is known as ‘madii’ [Kannada word]. Clear mind leads to happiness. All grief disappears on its own. This results in grief less happiness.
A clear mind helps one to understand the Lord. Impure mind can never understand Lord. Once one has understood the Lord, there is no grief. Intellect at this stage will be determined enough to understand the knowledge of the Lord and remain there.
At this stage, all thinking, thoughts lead to Lord only. Irrespective what is viewed or heard, they all represents the miracle of the Lord, who is the universal force behind it. One will not worry about the smaller events and thoughts. The clear mind is filled with Lord. Once the Lord fills the mind, everything becomes happiness. There is no limit to such happiness.