(Thwaha) 20 : 6
لَهُ مَا فِي السَّمَاوَاتِ وَمَا فِي الْأَرْضِ وَمَا بَيْنَهُمَا وَمَا تَحْتَ الثَّرَىٰ
To Him belongs whatever is in the heavens and whatever is on the earth and whatever is between them and whatever is under the nether worlds.
Just like 7 heavens, there are 7 levels of the earth as told in verse 65: 12. Just like Sidrathul Munthaha in the utmost top of heavens, the place beneath the 7th level of the earth is called “Thara” (netherworlds). See explanation 1: 7; 15: 44; 18: 100-101 and 107.