﴿ وَتَتَّخِذُونَ مَصَانِعَ لَعَلَّكُمْ تَخْلُدُونَ ﴾

“and make for yourselves mighty castles, [hoping] that you might become immortal?”

And you set up structures for extracting water underground that perhaps you might as though you will last forever therein and not die.