Bhagavad Gita 1.45

Alas, it is strange that we should be willing to kill our own countrymen and commit a great sin, in order to enjoy the pleasures of kingdom.

अहो बत महत्पापं कर्तुं व्यवसिता वयम्।
यद्राज्यसुखलोभेन हन्तुं स्वजनमुद्यताः॥

aho bata mahatpāpaṃ kartuṃ vyavasitā vayam|
yadrājyasukhalobhena hantuṃ svajanamudyatāḥ||

English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).