﴿ وَلَا تَشْتَرُوا۟ بِعَهْدِ ٱللَّهِ ثَمَنًۭا قَلِيلًا ۚ إِنَّمَا عِندَ ٱللَّهِ هُوَ خَيْرٌۭ لَّكُمْ إِن كُنتُمْ تَعْلَمُونَ ﴾

(And purchase not a small gain at the price of Allah's covenant) i.e. swearing by Allah falsely to obtain a small worldly gain. (Lo! that which Allah hath) of reward (is better for you) than what you have of wealth, (if ye did but know) the reward of Allah; it is also said that this means: if you believe in the reward of Allah.