Chapter 2 · verse 32 · gita.yoga.org

Bhagavad Gita 2.32

यदृच्छया चोपपन्नं स्वर्गद्वारमपावृतम्। सुखिनः क्षत्रियाः पार्थ लभन्ते युद्धमीदृशम्

Happy are the Kshatriyas, O Arjuna! who are called to fight in such a battle that comes of its own accord as an open door to heaven.