So they set out, until when they met a boy, al-Khidh r killed him. [Moses] said, "Have you killed a pure soul for other than [having killed] a soul? You have certainly done a deplorable thing." [18:74]
Random Hadith
Malik related to me from Zayd ibn Aslam from his father that Umar ibn al-Khattab came upon Abu Bakr as-Siddiq pulling his tongue. Umar said to him, "Stop, may Allah forgive you!" Abu Bakr replied, "This has brought me to dangerous places." [Malik 56:12]