The Proof of Sending Curses(Lanat) on Yazid!

The Proof of sending Lanat upon Yazid is derived from this (ayah), as was mentioned by Al-Barzanji (rah) in his Al-Ashaat and Imam Haythami (rah) in As-Sawaiq from Imam Ahmed (rah) that his son Abdullah asked him about sending Lanah on Yazid, and how sending Lanah upon him is mentioned in the book of Allah (i.e. Quran). Imam Ahmed (rah) in proof of (sending Lanah upon Yazid) mentioned these verses:Would ye then, if ye were given the command, work corruption in the land and sever your ties of kinship? Such are the men whom Allah has cursed…(47:22-23), So could there be a greater fitnah than the actions committed by Yazid? 

[Ruh ul Ma’ani by Imam Al-Alusi, Volume 9 Under Surah Muhammad 22-23]
 

Cursing Yazeed from traditions (Ahadith) :

It has been narrated on the authority of Hadhrat Abu 'Ubaidah bin Jarrah (May Allah be well pleased with him) that the Holy Prophet (Sallallahu alaihi wa sallam) said:  The affairs of my Ummah will continue with justice. The first person to disrupt it will be a person from Banu Ummayya, who will be called Yazid. 

(Musnad Abu Ya'ala, Musnad Abu 'Ubaidah Raziallahu anhu).

The famous Expert in interpretation of Holy Quran Abul Fida Ismail bin 'Umar who is famously known as Ibn Kathir has recorded this Hadith in his book Al Bidayah Wan Nihayah in Vol. 6 PG No 256

The great Hadith-expert Imam Shahabuddin Ahmed Bin Hajr Makki Haithami (May Allah shower His mercy on him) has also recorded this Hadith in As Sawaaiq Al Muhriqa, Pg No. 132.  He has also recorded another Hadith in this connection in the same book on Pg No. 132:

It has been narrated on the authority of Hadhrat Abu Darda (May Allah be well pleased with him), he said: I heard the Holy Prophet (Sallallahu alaihi wa sallam): The first one to change my Sunnah will be a person from Banu Ummayya called Yazid.