Anantazhwar

The story goes that Ramanuja once asked Ananthalwar to raise a flower garden for the Lord on the Tirumala hill, that is Venkateswara. Ananthalwar abided by the request and went upon raising a garden. He took the help of his pregnant wife who found it difficult to do the manual labor from time to time. Lord Venkateswara having seen the trouble of the lady assumed the form of a young lad and helped her out. On one occasion when this came to the notice of Ananthalwar, the latter was furious and he hit the lad with a crowbar. The lad then disappeared but when Ananthalwar visited the god in Tirumala, he found that the Lord was bleeding from the chin. He at once realised that it was the Lord who had helped his wife and regretted his behavior. He applied raw camphor for the wound. Lord Venkateswara was impressed with Ananthalwar's devotion and not only forgave him but also told him that he would display the raw camphor forever as a mark of Ananhtalwar's devotion. Thus green camphor is applied to the Lord's chin to this day during the rituals. Even today you can see Sri Ananhtalwar's Crow bar when you enter the temple, hanging on right side. [1][2][3]

https://guruparamparai.wordpress.com/2013/03/31/ananthazhwan/