Luqmān was an Ethiopian Slavs who was a carpenter.
His master said to him:
"Slaughter this sheep for us," so he slaughtered it.
His master said: "Bring the best two pieces from it," so he brought out the tongue and the heart.
Them time passed, as much as Allāh willed, and his

master said: "Slaughter this sheep for us," so he slaughtered it.
His master said: "Bring the worst two morsels from it," so he brought out the tongue and the heart.
His master said to him: "I told you to bring out the best two pieces, and you brought these, then I told you

bring out the worst two pieces, and you brought these!"
Luqmān said: "There is nothing better than these if they are good, and there is nothing worse than these if they are bad."
● {تفسير ابن كثير ١٢/٣١}
Prophet ﷺ said: "Most of your sins are because of your tongues."