What is achieved by juxtaposing qiṣāṣ and life?

Musāwāt and Ījāz al-Qaṣr: Proportionate Wording and the Rhetoric of Qiṣāṣ

• An apparent contrast reveals deterrence and the preservation of life
• It proves that qiṣāṣ and life are unrelated
• It shows that contrasting words are always stylistically faulty
• It is only a rhyme technique