He did ghusl and prayed, then he realized that he had missed a part of his body and the water had not reached it

No File Exists
Check below answers in case you are looking for other related questions:
Does the presence of oil, ink or secretions of the eye affect tahaarah (purification)?
He did ghusl then he realized that the water had not reached his foot

No File Exists
Related Answers:
Ruling on using nail polish, and does it have to be removed when doing wudoo’
Is ghusl sufficient with no need for wudoo’?
She used to do the secret habit and did not do ghusl but she fasted and prayed
Does the presence of oil, ink or secretions of the eye affect tahaarah (purification)?
He did ghusl then he realized that the water had not reached his foot

Recommended answers for you:
Ruling on vinegar made from wine
Ruling on sexual fantasies
Eating habits and diet of the Prophet (peace and blessings of Allaah be upon him)
How to pray the two rak‘ahs on the wedding night
Temporary and permanent tattoos – types and rulings