The most despised and abhorrent action is pride

Once Hazrat Thaanwi (Rahmatullahi Alaihi) mentioned:

According to my understanding, nothing can be more despicable than pride. I detest the sin of pride more than any other sin. Even though there are many grave sins such as committing adultery, consuming intoxicants, etc. which are extremely serious, however, I have a natural aversion and hatred for pride due to it being a branch of shirk. Despite Allah Ta’ala being the greatest, by regarding oneself to be great and better than others, one has attributed greatness to oneself. Hence is this not a type of shirk? A proud person, who is a mere slave, is in actual fact attributing a quality (greatness) to himself which is exclusive for Allah Ta’ala. (Malfoozaat Hakeemul Ummat 10/ 54)