﴿ وَكَانُوا۟ يَنْحِتُونَ مِنَ ٱلْجِبَالِ بُيُوتًا ءَامِنِينَ ﴾

“notwithstanding that they had been wont [to enjoy Our blessings and] to hew out dwellings from the mountains, [wherein they could live] in security”

Please check ayah 15:84 for complete tafsir.