Shloka 4.39.2
वानरसेनामिलनम् / The Mustering of the Vanara Hosts
यदिन्द्रो वर्षते वर्षं न तच्चित्रं भवेत्क्वचित्।आदित्यो वा सहस्रांशुः कुर्याद्वितिमिरं नभः।।4.39.2।।चन्द्रमा रश्मिभिः कुर्यात्पृथिवीं सौम्य निर्मलाम्।त्वद्विधो वाऽपि मित्राणां प्रतिकुर्यात्परन्तप ।।4.39.3।।
yad indro varṣate varṣaṁ na tac citraṁ bhavet kvacit |
ādityo vā sahasrāṁśuḥ kuryād vitimiraṁ nabhaḥ || 4.39.2 ||
candramā raśmibhiḥ kuryāt pṛthivīṁ saumya nirmalām |
tvad-vidho vāpi mitrāṇāṁ pratikuryāt parantapa || 4.39.3 ||
O gentle Sugrīva, scorcher of foes—there is nothing strange if Indra sends rain, if the thousand-rayed Sun drives darkness from the sky, and if the Moon with his beams makes the earth serene, bright, and cool; likewise it is only fitting that one like you should repay the kindness of friends.
'O scorcher of enemies, gentle Sugriva! it will not be strange if Indra showers rain, if the Sun in the sky dispels darkness with his thousand rays, and if the Moon cools down the earth with his light, and a person like you helps his friend.
Mitradharma—repaying and supporting friends who have helped you; gratitude and reciprocity are presented as natural and righteous, like rain from Indra or light from the Sun and Moon.
In the Kishkindhā alliance, Rāma underscores that Sugrīva’s assistance to his friends (especially Rāma and Lakṣmaṇa) is not extraordinary but the proper, expected course of dharma.
Kṛtajñatā (gratitude) and reliability in friendship—acting faithfully toward allies and returning help received.