Both words mean "believers" in Arabic, specifically referring to Muslims. The difference lies in their grammatical function and the context in which they are used.
* مُؤْمِنِينَ (mu'minīn): This form is the nominative plural of "mumin." It is used when the believers are the subject of the sentence.
Example:
* المؤمنون يدعون الله. (Al-mu'minūn yad'ūna Allaha.) - The believers call upon God.
* مُؤْمِنُونَ (mu'minūn): This form is the accusative plural of "mumin." It is used when the believers are the object of the sentence.
Example:
* رأيت المؤمنين يصليون. (Ra'aytu al-mu'minīn yusallūn.) - I saw the believers praying.
In essence:
* مُؤْمِنِينَ (mu'minīn): Used when the believers are performing the action.
* مُؤْمِنُونَ (mu'minūn): Used when the believers are the ones being acted upon.
The difference is subtle but crucial for correct Arabic grammar.