military obligation

وَإِنَّ مِنكُمْ لَمَن لَّيُبَطِّئَنَّ فَإِنْ أَصَـٰبَتْكُم مُّصِيبَةٌ قَالَ قَدْ أَنْعَمَ ٱللَّهُ عَلَىَّ إِذْ لَمْ أَكُن مَّعَهُمْ شَهِيدًا

And indeed, there is among you he who lingers behind; and if disaster strikes you, he says, "Allāh has favored me in that I was not present with them."