Sufyan al-Thawri R: Partners in Sins of Extravagance
One day Sufyan al-Thawri R, with a friend, was passing the door of a notable. The friend gazed at the portico (porch/entrance to a building). Sufyan rebuked him, "If you and your like did not gaze so at their palaces, they would not commit such extravagance. By gazing you become partners in the sin of this extravagance."
Source: Tadhkirat al-Awliya
Sufyan ath-Thawri ibn Said (716–778) was a tabi’i Islamic scholar, Hafiz and jurist, founder of the Thawri madhhab.