The Prophet ﷺ said, "None of you should say Khabuthat Nafsi, but he is recommended to say 'Laqisat Nafsi."

عَنِ النَّبِيِّ ﷺ قَالَ لاَ يَقُولَنَّ أَحَدُكُمْ خَبُثَتْ نَفْسِي وَلَكِنْ لِيَقُلْ لَقِسَتْ نَفْسِي

from the Prophet ﷺ, who said: "None of you should say, 'My soul has become foul,' but rather let him say, 'My soul has become remorseless.'"

عَنِ النَّبِيِّ ﷺ قَالَ: «لاَ يَقُولَنَّ أَحَدُكُمْ خَبُثَتْ نَفْسِي، وَلَكِنْ لِيَقُلْ: لَقِسَتْ نَفْسِي».