What does the author say about refusing permitted lifesaving sustenance in severe hunger until death?

Prescribed Acts and Prohibitions: Fard, Wajib, Sunnah, Nafl, Haram, Makruh, Azimah and Rukhsah

• Refusal is always required and best
• The refusal has no legal significance
• The refusal becomes an additional voluntary act equal to fard
• Refusal of the permitted means of survival in those conditions is sinful