وَهِىَ تَجْرِى بِهِمْ فِى مَوْجٍ كَٱلْجِبَالِ وَنَادَىٰ نُوحٌ ٱبْنَهُۥ وَكَانَ فِى مَعْزِلٍ يَـٰبُنَىَّ ٱرْكَب مَّعَنَا وَلَا تَكُن مَّعَ ٱلْكَـٰفِرِينَ Qur’an Hud (11:42)Wahiya tajree bihim fee mawjin kaaljibali wanada noohunu ibnahu wakana fee maAAzilin ya bunayya irkab maAAana wala takun maAAa alkafireena
The diminutive in ya bunayya (lit., "O my little son") is an expression of endearment irrespective of a son's age: for instance, Noah's son appears in the above story as a grown man, while Joseph, similarly addressed by his father in 12:5 , was a child or, at the most, an adolescent.
The simile of mountains applies to the waves, which were mountain high, -literally, for the peaks were being submerged.