It is narrated from Jabir (may Allah be pleased with him) that at the place of Batn Nakhl (a settlement near Madinah), the Messenger of Allah (peace and blessings be upon him) led the people in the Zuhr prayer during a time of fear. He led one group in two rak‘ahs and then said salam. Then the second group came, and he led them in two rak‘ahs and then said salam.
Hadith Referenceمسند الإمام الشافعي / كتاب الصلاة / 368
Hadith Takhrijأخرجه النسائي: صلاة الخوف (1555) وصححه ابن خزيمة (1353).