Ma'arif al-Qur'an
Mufti Muhammad ShafiExplanation of Difficult Words1. The word السَّدَّ used in the expression: بَيْنَ السَّدَّيْنِ denotes what be-comes a barrier against something. It may be a wall or mountain and it may be natural or artificial. At this place, the word: السَّدَّيْنِ (as-saddain) means two mountains that stood as a barrier against the intrusion of Ya'juj and Ma'juj. But, they still attacked through the pass in between the two mountains and which was closed by Dhul-Qarnain.2. The word: زُبَرَ (zubar) in: زُبَرَ الْحَدِيدِ (zubar al-hadid - 96) is the plural of: زُبرہ (zubrah) which means sheets in the sense of pieces, fragments or ingots of iron which were to be used in the wall designed to block the pass, obviously a stronger device as compared to bricks and rocks.3. The word: الصَّدَفَيْنِ (as-sadafain - 96) signifies the two sides of the mountain facing each other.4. According to most commentators, the last word: قِطْرًا (qitr) in verse 96 means molten copper. There are some others who have explained 'qitr' as molten iron or pewter.
(al-Qurtubi)The expression: دَكَّاءَ (dakkaa'a - 98) used about the wall means what would crumble down to the level of the ground.