Translation:

6. Truly Man is to his Lord ungrateful;

Notes (Tafseer)

6246. Man, i.e., unregenerate man, in contrast to those who receive guidance and wage unceasing war with Evil, is ungrateful to his Lord and Cherisher, Him Who created him and sustains him, and sends His blessings and favours at all times. The ingratitude may be shown by thoughts, words, and deeds,-by forgetting or denying Allah and His goodness, by misusing His gifts, or by injustice to His creatures.