Mantra 12

आत्मानं चेद्विजानीयादयमस्मीति पुरुषः ।किमिच्छन् कस्य कामाय शरीरमनु संज्वरेत् ॥४,४.१२ ॥

In plain words

If a person truly knows the Self as 'I am this,' then wishing what and for whose desire should he suffer along with the body?