Cold and heat, pleasure and pain, appear and then pass away.

When sensation and its object come into contact, feelings such as coldness or heat, pleasure or pain arise. All of them strongly move us, but they have a beginning and an end, and are temporary experiences that appear and then pass away.

Therefore, Krishna teaches us to "endure." This does not mean to feel nothing, nor does it mean to silently accept dangers or harms that can be avoided. It is not a teaching that forbids seeking necessary help and making judgments to avoid harm; rather, it means not allowing fleeting pleasures and pains to dominate the center of one's mind and judgment. Even in the midst of suffering, we must recognize that it is not something that will last forever.

Japanese Translation from the Geeta Press Edition - Chapter 2, Section 14: "The Contact of Senses Passes Away"

In the previous section, we demonstrated that the soul is eternal and immutable, and established that it is not wise for the Lord to lament about the soul. However, here, a question may arise: even if the soul is eternal and immutable, does the union and separation with relatives not actually bring about experiences of pleasure and pain? Then, how can one avoid sadness?

In response to this, the speaker declares that all contact and separation are inherently temporary, and that both the pleasure and pain arising from them should be endured.

Sanskrit original text

मात्रास्पर्शास्तु कौन्तेय शीतोष्णसुखदुःखदाः ।
आगमापायिनोऽनित्यास्तांस्तितिक्षस्व भारत ॥ १४ ॥

Romanization

mātrāsparśās tu kaunteya śītoṣṇasukhaduḥkhadāḥ |
āgamāpāyino 'nityās tāṃs titikṣasva bhārata || 14 ||

O son of Kunti, contact between the senses and their objects creates sensations such as pleasure and pain. These are temporary manifestations that arise and then disappear. Therefore, Arjuna, you should endure them. (14)

Things that measure, or things by which one obtains knowledge about things, are called "Mātrā." Therefore, in this context, the word "Mātrā" means all sensations, including the mind. Also, "Sparśa" means contact. Thus, the compound term "Mātrāsparśāḥ" refers to the fact that the mind and senses come into contact with their respective objects, namely sound, touch, color, taste, and smell.

In this section, the terms "cold and heat," "pleasantness and unpleasantness," etc., represent all opposing pairs. Therefore, when the author says that sensations are produced by contact between a sense organ and its object, such as in the case of cold and heat or pleasantness and unpleasantness, it indicates that all dualistic experiences arise through this interaction between sensation and object. For example, these include "cold and heat," "love and hate," "joy and sorrow," "pleasantness and unpleasantness," and "harmony and discord."

All pathological emotions arise from the perception of sensory objects as permanent. Therefore, it is necessary to know and realize that these objects are inherently temporary and transient.

That contact must not be allowed to cause unhealthy reactions in one's heart.

The speaker depicts the interaction between sensation and its object as something that inherently appears and disappears, a temporary phenomenon. And he is urging Arjuna to go beyond this. By doing so, the speaker indicates that such interactions, which create pleasure and pain, are temporary and contain no true happiness.

Therefore, Arjuna is advised to endure them. In other words, he is asked not to be happy or sad about their appearance or disappearance, and not to have any liking or prejudice towards them.

Encounters with loved ones are also included in this. Because we connect with and separate from relatives through the mind and senses, just like other objects. Therefore, it should be understood that the Lord is urging Arjuna to overcome the pleasure and pain arising from such every contact and separation.