What is the ruling on one who prayed but did not establish the prayer

Question : Yes. A man prayed but did not establish the prayer, so what is the ruling on his prayer?

Answer : If he prayed but did not establish the prayer, his prayer is valid. However, if they were in congregation, they have sinned by leaving off the iqamah, because the iqamah is a collective obligation (fard kifayah) for them. If he was alone, the scholars have mentioned that the iqamah for the one praying alone is a recommended practice (sunnah) and not obligatory, so he has not sinned in that case. As for the prayer, it is valid in every case.