I think edip is revering to this aya in Al Nisa
(1) Allah loveth not the utterance of harsh speech save by one who hath been wronged. Allah is ever Hearer, Knower.
( سورة النساء , An-Nisa, Chapter #4, Verse #148)
But I think your insult should not insult only you, wich i believe habbens when you show the finger to someone.
In the quran it also says
O ye who believe! Be steadfast witnesses for Allah in equity, and let not hatred of any people seduce you that ye deal not justly. Deal justly, that is nearer to your duty. Observe your duty to Allah. Lo! Allah is Informed of what ye do.
( سورة المائدة , Al-Maeda, Chapter #5, Verse #8)
Be modest in thy bearing and subdue thy voice. Lo! the harshest of all voices is the voice of the ass.
( سورة لقمان , Luqman, Chapter #31, Verse #19)
You freed yourself to much