Musnad Ahmad 3966

It was narrated from Zirr bin Hubaish from Ibn Mas'ood that He was cutting siwak from an arak tree; he had skinny legs and the wind was pushing him. The people laughed at him and the Messenger of Allah (ﷺ) said: “What are you laughing at?” They said: O Prophet of Allah, at the thinness of his legs. He said. "By the One in Whose hand is my soul, they weigh more heavily in the Balance than Uhud."