Imam al-Hasan al-Basri رحمه الله said:
“ It has reached me that when Allah the Mighty and Majestic blesses a people and gives them some good, He asks them to be grateful. If they are grateful, He is all-able to give them more. But if they are ungrateful, He is all-able to turn His blessings into a punishment. “
{Related by Imam Al-Bayhaqi, Shu’ab Al-Iman}