Shloka 6.25.20
शुकसारण-चारप्रवेशः (Suka and Sāraṇa’s Espionage and Release)
नचेदंग्रहणंप्राप्यभेत्तव्यंजीवितंप्रति ।न्यस्तशस्त्रौगृहतौवानदूतौवधमर्हतः ।।।।
na ced aṃ grahaṇaṃ prāpya bhettavyaṃ jīvitaṃ prati | nyastaśastrau gṛhītau vā na dūtau vadham arhataḥ ||
Since you have been seized, you need not fear for your lives. Those who have laid down their weapons, or those taken captive—and especially envoys—do not deserve to be slain.
As you have been caught by us like this you need not have apprehension of your life. Those who do not possess wield or those who are envoys ought not to be slayed.
Dūta-dharma and yuddha-nīti: envoys and those who are disarmed/captive are protected classes; righteous war restrains violence by rules.
Śuka and Sāraṇa are caught while spying; Rāma prevents their execution and assures them of safety.
Rāma’s justice and self-control—he enforces ethical boundaries even in a hostile war.