He was not sure about the number of prostrations, and he omitted the prostration of forgetfulness out of ignorance; what is the ruling on his prayer?

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Check below answers in case you are looking for other related questions:
If a person does not do the obligatory prostration of forgetfulness
Can sujood al-sahw be made up for later?

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Related Answers:
Sujood ul-sahw (prostration for forgetfulness) if one joins congregation late
What should be said in the two prostrations of forgetfulness and in between them?
He did the first sajdah of sujood al-sahw (prostrations for forgetfulness in the prayer), then he remembered that he did not do anything that required sujood al-sahw
If a person does not do the obligatory prostration of forgetfulness
Can sujood al-sahw be made up for later?

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