It’s not about being careful with your words. 
It’s about asking yourself why these words come to mind? What is it about this person that triggered a knee jerk reaction in you? 
It’s not about Isa. It’s about him. 
She’s merely a mirror or reflection to something in him that he lacks, hates, fears or resists. 

Do some shadow work. 
Get to know yourself better, and what has you tick. 

Then the “words” part becomes the easy part.