Was the wearing of a costly garment worth 400 dinars by Abu Hanifa a subject of prohibition, and was his response that the prohibition is for those who are ostentatious, and not for him?

The story referred to is unknown, and it is known that Abu Hanifa was of good appearance and clothing. Letting one's garment hang below the ankles (isbal) is forbidden if done out of arrogance, and there is a difference of opinion if it is done without arrogance. The majority opinion is that it is not forbidden in this case, though the Hanafis consider it subtly disliked (karahat tanzih).