ليؤمنن
Appears 2 times in the Quran. (Root: امن)
-
6:109 وَأَقْسَمُواْ بِاللّهِ جَهْدَ أَيْمَانِهِمْ لَئِن جَاءَتْهُمْ آيَةٌ لَّيُؤْمِنُنَّ بِهَا قُلْ إِنَّمَا الْآيَاتُ عِندَ اللّهِ وَمَا يُشْعِرُكُمْ أَنَّهَا إِذَا جَاءَتْ لاَ يُؤْمِنُونَ
And they swear by Allah with the strongest of their oaths, that if a sign came to them they would most certainly believe in it. Say: Signs are only with Allah; and what should make you know that when it comes they will not believe?
-
4:159 وَإِن مِّنْ أَهْلِ الْكِتَابِ إِلاَّ لَيُؤْمِنَنَّ بِهِ قَبْلَ مَوْتِهِ وَيَوْمَ الْقِيَامَةِ يَكُونُ عَلَيْهِمْ شَهِيدًا
And there is not one of the followers of the Book but most certainly believes in this before his death, and on the day of resurrection he (Isa) shall be a witness against them.