A verse and its Tafsir
Allah the Exalted says:
"And remember when your Lord proclaimed: 'If you are grateful, I will surely increase you [in favor];
but if you deny, indeed, My punishment is severe.'"
The meaning of gratitude is clear and well-known.
As for the denial mentioned in this verse,
it refers to the denial of blessings,
which is the opposite of gratitude.
Whoever is grateful for a blessing is promised an increase,
and whoever denies it is warned of a severe punishment.