While we were in an army, Messenger of Allah ﷺ came to us and said, "You have been allowed to do the Mut'a (marriage), so do it."
عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ وَسَلَمَةَ بْنِ الأَكْوَعِ قَالاَ كُنَّا فِي جَيْشٍ فَأَتَانَا رَسُولُ اللَّهِ ﷺ فَقَالَ إِنَّهُ قَدْ أُذِنَ لَكُمْ أَنْ تَسْتَمْتِعُوا فَاسْتَمْتِعُوا