Surah Sad 38:46

إِنَّآ أَخْلَصْنَـٰهُم بِخَالِصَةٍ ذِكْرَى ٱلدَّارِ

Indeed, We chose them for an exclusive quality: remembrance of the home [of the Hereafter].

Translation: Saheeh International

Tafsir

Assuredly We purified them with an exclusive thought namely the remembrance of the Abode of the Hereafter in other words to always remember it and to work for it a variant reading for bi-khālisatin dhikrā’l-dār has the genitive construction bi-khālisati dhikrā’l-dār making this dhikrā al-dār ‘remembrance of the Abode’ …

Excerpt from Tafsir al-Jalalayn, commentary on 38:46, via Quran.com. The reader has the full commentary and 9 more tafsirs.