'A'isha reported that the Prophet, may Allah bless him and grant him peace, said, "None of you should say, 'khabuthat nafsi'. He should say, 'Laqisat nafsi.'"  

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

Same with another isnad.  

رَسُولِ اللهِ ﷺ قَالَ لاَ يَقُولَنَّ أَحَدُكُمْ خَبُثَتْ نَفْسِي وَلْيَقُلْ لَقِسَتْ نَفْسِي