Our happiness or misery arise essessntially when we see happiness or sorrow in others.

यो दुःखितानि भूतानि दृष्ट्वा भवति दुःखितः। 

सुखितानि सुखी वापि स धर्मं वेद नैष्ठिकम्॥ 

इन्दिश्चे स्प्रूचे ५५९५ २५३३ विक्र्माङ्कदेवचरिते

yo duḥkhitāni bhūtāni dṛṣṭvā bhavati duḥhitaḥ| 

sukhitāni sukhī vāpi sa dharmaṁ veda naiṣṭhikam|| 

ndiśce sprūce 5595 (2533) vikrmāṅkadevacarite

A human being who becomes sad when he sees fellow humans suffer, and who would celebrate heartily when all people around ae happy, is the one who has understood Dharma or law of righteousness in letter and spirit.

We human beings are not islands or beings living in isolation. Our happiness or misery arise essessntially when we see happiness or sorrow in others. If a fellow feels happiness or cruel satisfaction when he sees misery in others, then he is just sick, he requires treatment.

 

यः who, a person दुःखितानि in grief भूतानि beings दृष्ट्वा having seen दुःखितः भवति. Becomes sad सुखितानि in happiness, in comfort दृष्ट्वा seeing सुखी happy अपि too भवति वा becomes, in turn . सःhe नैष्टिकं in the proper sence, in depth धर्मं वेद understands the law of propriety, Dharma