AL FAT-H (KEMENANGAN) — Ayat 16
قُل لِّلْمُخَلَّفِينَ مِنَ الْأَعْرَابِ سَتُدْعَوْنَ إِلَى قَوْمٍ أُوْلِي بَأْسٍ شَدِيدٍ تُقَاتِلُونَهُمْ أَوْ يُسْلِمُونَ فَإِن تُطِيعُوا يُؤْتِكُمُ اللَّهُ أَجْرًا حَسَنًا وَإِن تَتَوَلَّوْا كَمَا تَوَلَّيْتُم مِّن قَبْلُ يُعَذِّبْكُمْ عَذَابًا أَلِيمًا
Say to those who remained behind of the bedouins, "You will be called to [face] a people of great military might; you may fight them, or they will submit. So if you obey, Allah will give you a good reward; but if you turn away as you turned away before, He will punish you with a painful punishment."
Tafsir
{Say to those of the bedouins who stayed behind} mentioned as a test {You will be called to a people of} people of {great prowess} It was said that they are the Banu Hanifa, the people of Yamamah, and it was said that they are the Persians and the Romans {fight them} is an implied state, which is what is called to in meaning {or} they {submit} so do not fight {then if you obey} to fight them {Allah will give you a good reward. But if you turn away as you turned away before, He will punish you with a painful punishment} painful.