Tafsir of Al-Jinn 72:13

وأنا لما سمعنا الهدى آمنا به

And indeed when we heard the Guidance, we believed therein, They were proud of this, and it is something for them to be proud of, as well as a great honor for them and a good characteristic. Concerning their statement,

فمن يومن بربه فﻼ يخاف بخسا وﻻ رهقا

and whosoever believes in his Lord shall have no fear, either of a decrease in the reward of his good deeds or an increase in the punishment for his sins. Ibn `Abbas, Qatadah and others said, "This means, he should not fear that the reward for his good deeds will be decreased or that he will be burdened with anything other than his sins.'' This is as Allah says,

فﻼ يخاف ظلما وﻻ هضما

Then he will have no fear of injustice, nor of any curtailment. (20:112)