Ibn Jarir (رحمه الله) recorded that Khalid ar-Raba‘i said:
“Luqman was an Ethiopian slave who worked as a carpenter. His master once said to him, ‘Slaughter this sheep for us,’ and he slaughtered it.
His master then said, ‘Bring me the best two parts of it,’ so Luqman brought the tongue and the heart.
After some time had passed, as Allah willed, his master again said, ‘Slaughter this sheep for us,’ and he slaughtered it.
His master said, ‘Bring me the worst two parts of it,’ and Luqman again brought the tongue and the heart.
His master said, ‘I asked you to bring the best two parts, and you brought these; then I asked you to bring the worst two parts, and you brought the same!’
Luqman replied, ‘There is nothing better than the tongue and the heart when they are good — and nothing worse than them when they are bad.’”
— Tafsir Ibn Kathir, Surah Luqman (31:12)
The Enduring Good Deeds 