Malik related to me from Zayd ibn Aslam from his father that Umaribn al-Khattab came upon Abu Bakr as-Siddiq pulling his tongue. Umarsaid to him, "Stop, may Allah forgive you!" Abu Bakr replied, "Thishas brought me to dangerous places." (AR)
USC-MSA web (English) reference: Book 56, Hadith 12 (AR)
Arabic reference (AR): Book 56, Hadith 1825 (AR)