A write up series by Chandarsekharan Raman.
(Thanks to Chandru for sharing his insight of Sri MahaPeriyava through Bhagavad Gita)
In the Bhagavad Gita, when Arjuna was inflicted by extreme sorrow, Lord Krishna instructs Arjuna about the transitory nature of happiness and sorrow.
मात्रास्पर्शास्तु कौन्तेय शीतोष्णसुखदुःखदाः |
आगमापायिनोऽनित्यास्तांस्तितिक् षस्व भारत || 2-14||
O, Kaunteya (Arjuna)! The contacts of the sense organs with the sensory world that give rise to cold and heat, happiness and sorrow, which have the nature of coming and going, are not constant. Endure them, Bharata (Arjuna)!
Adi Shankaracharya, when commenting on this verse, remarks that cold (and similarly heat) could bring pleasure and pain depending on the situation. But happiness always bring pleasure and sorrow always brings pain! Even then, Lord Krishna puts them in the same category as cold and heat — (śīta, uṣṇa, sukha & duḥkha), because all of them are not permanent (anityāḥ)!
सकृत्स्मरण मात्रेण भवरोग विनाशके |
श्री चन्द्रशेखरपादाब्जे भासेताम् हृदि मे सदा ||
Article Courtesy: Remembering MahaPeriyava Write-Up Series