Quran 18:93

حَتَّىٰٓ إِذَا بَلَغَ بَيۡنَ ٱلسَّدَّيۡنِ وَجَدَ مِن دُونِهِمَا قَوۡمً۬ا لَّا يَكَادُونَ يَفۡقَهُونَ قَوۡلاً۬ ٩٣

When he reached the valley between two palisades, he found people whose language was barely understandable.