What is the ruling on mispronouncing the word "mustaqīm" (مستقيم) by emphasizing the "tāʾ" to sound like a "ṭāʾ," and the word "wa barakātuh" (وبركاته) by pronouncing it as "wa barakātoh"?

If a worshipper pronounces the word "mustaqim" (straight) by emphasizing the "ta" sound in such a way that it sounds like a "ṭa" (طاء), this is an error and a linguistic mistake. If this occurs outside of prayer, he should correct it. As for prayer, if it occurs in Al-Fatiha (Al-Mustaqim - the Straight Path), the majority of scholars hold that Al-Fatiha is a pillar of prayer. However, some scholars have shown leniency regarding letters that are close in pronunciation, deeming the prayer valid due to the difficulty of avoiding such mistakes and the widespread nature of the issue. Some have also differentiated between the prayers of common people and those of jurists.

As for pronouncing "wa barakātu" as "wa barakātu" (وبركاتو instead of وبركاته), this is a clear linguistic error. If this occurs in the final Tashahhud, which is considered a pillar by some jurists, then the prayer is invalid. However, one can adopt the less preferred opinion after the act has occurred. Ibn Taymiyyah held that whoever omits a condition or a pillar out of ignorance is not required to repeat the prayer. He must, however, pay attention and correct the error in future prayers.