The Prophet ﷺ led 300 sahaba out from Madinah against the Banu Lahyan. This was the tribe that, two years earlier, had tricked a group of sahaba into coming to them and then massacred them at al-Raji. As was his tactic, the Prophet ﷺ did not at first say where they were going. But the Banu Lahyan were warned in advance and fled. When the Muslims reached their camp it was empty, and no battle took place.
The Banu Lahyan had asked the Quraysh for help, and the Quraysh sent a small force under Khalid ibn al-Walid. It camped facing the Muslims, within sight of them. When the time for Zuhr came, the Muslims prayed in congregation and set aside their weapons and armor. A man in Khalid's camp said that this would be the perfect moment to attack. Khalid replied that another such chance would come at Asr. Before Asr came, Allah revealed a verse of Surah al-Nisa that set out Salat al-Khawf, the prayer of fear. It tells the Muslims to pray in groups taking turns, keeping their weapons with them, when they face an enemy.
Outcome: No engagement took place; the camp of the Banu Lahyan was found empty.
Most likely the occasion of the legislation of Salat al-Khawf (Qur'an 4:102).
Other events recorded in 6 AH. Their order within the year is not established; use the storyline above for the sequence.
If only they were to do this again, this is the perfect time to attack.
Said to Khalid ibn al-Walid after the Muslims, praying Zuhr in congregation, had set aside their weapons and armor.
Indeed, they have another time coming up (Asr).
اللّهُمّ إِنّي أَعُوذُ بِكَ مِنْ وَعْثَاءِ السّفَرِ، وَكَآبَةِ الْمَنْظَرِ، وَسُوءِ الْمُنْقَلَبِ فِي الْمَالِ وَالأَهْلِ
O Allah, I seek refuge in You from this journey's hardships, and from the wicked sights in store, and from finding our family and property in misfortune upon returning.
آيِبُونَ، تَائِبُونَ، عَابِدُونَ، لِرَبّنَا حَامِدُونَ
We are returning, repentant, worshiping our Lord and praising Him.
وَإِذَا كُنتَ فِيهِمْ فَأَقَمْتَ لَهُمُ الصَّلَاةَ فَلْتَقُمْ طَائِفَةٌ مِّنْهُم مَّعَكَ وَلْيَأْخُذُوا أَسْلِحَتَهُمْ فَإِذَا سَجَدُوا فَلْيَكُونُوا مِن وَرَائِكُمْ وَلْتَأْتِ طَائِفَةٌ أُخْرَىٰ لَمْ يُصَلُّوا فَلْيُصَلُّوا مَعَكَ وَلْيَأْخُذُوا حِذْرَهُمْ وَأَسْلِحَتَهُمْ ۗ وَدَّ الَّذِينَ كَفَرُوا لَوْ تَغْفُلُونَ عَنْ أَسْلِحَتِكُمْ وَأَمْتِعَتِكُمْ فَيَمِيلُونَ عَلَيْكُم مَّيْلَةً وَاحِدَةً ۚ وَلَا جُنَاحَ عَلَيْكُمْ إِن كَانَ بِكُمْ أَذًى مِّن مَّطَرٍ أَوْ كُنتُم مَّرْضَىٰ أَن تَضَعُوا أَسْلِحَتَكُمْ ۖ وَخُذُوا حِذْرَكُمْ ۗ إِنَّ اللَّهَ أَعَدَّ لِلْكَافِرِينَ عَذَابًا مُّهِينًا
“When you [O Prophet] are [campaigning] with them and you lead them in prayer, let one group of them pray with you — while armed. When they prostrate themselves, let the other group stand guard behind them. Then the group that has not yet prayed will join you in prayer — and let them be vigilant and armed. The disbelievers would wish to see you neglect your weapons and belongings, so they could launch a sweeping assault on you. But there is no blame if you lay aside your weapons when overcome by heavy rain or illness — but take precaution. Indeed, Allah has prepared a humiliating punishment for the disbelievers.”
Most likely the occasion of the legislation of Salat al-Khawf.