It has nothing to do with issue of Allah having no power over him.
It has nothing to do with issue of Allah having no power over him. If Yúnus had committed no sin by leaving his people, then why did he say that, “surely I am one of the ¨alimeen, the unjust”? As mentioned earlier in the case of Prophet Adam (a.s.), the word ¨ulm does not necessarily imply “injustice” and “sin”. It also means “to make haste” and “to come to harm”. Any of these two meanings are compatible with the concept of 'ismah and also correct in the case of Prophet Yúnus.
The verse would then mean as follows: “There is no god but You, glory be to Thee; surely I am one of those who make haste” or “There is no god but You, glory be to Thee; surely I am one of those who come to harm”.
This explanation is further supported by the next verse in which Allah says, “So We responded to him and delivered him from the grief, and thus do We deliver the believers.” The ¨ulm mentioned in the prayer of Yúnus is explained by Allah as ” al-ghamm —grief”, and not as sin or injustice; that is why Allah said ” najjayna —delivered” and not “forgiven”. Previous…