I took a bath without making the intention to purify myself from Janabah (major ritual impurity related to sexual discharge), as I thought I was in a state of Taharah (ritual purity). After bathing, I remembered that I was Junub (in a state of post-sexual ritual impurity)
before taking the bath. Must I repeat Janabah Ghusl (full ritual bath to cleanse of sexual discharge)? Or does the bath I took serve as purification from Janabah?
If you intended merely to clean or cool yourself, you must repeat Ghusl with the intention of purifying yourself from Janabah, as you did not make this intention in the first bath. The Prophet (peace be upon him) said:
Deeds depend upon the intentions.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.