Answered by Ustadh Tabraze Azam
Question: Assalam alaykum
If one is praying alone and aloud (with the intention that someone may join him in congregation) and then in mid-prayer forgets to recite the takbir aloud (no one has joined him in prayer as of this point), does one have to perform the prostration of forgetfulness?
Answer: Assalamu alaykum wa rahmat Allah,
No, it is not necessary (wajib) for a person praying alone to raise their voice, and thus, if you forget to do so, or if you change from loud to quiet, it doesn’t affect the soundness of your prayer.
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And Allah Most High alone knows best.
[Ustadh] Tabraze Azam
Checked and Approved by Shaykh Faraz Rabbani
Ustadh Tabraze Azam holds a BSc in Computer Science from the University of Leicester, where he also served as the President of the Islamic Society. He memorised the entire Qur’an in his hometown of Ipswich at the tender age of sixteen, and has since studied the Islamic Sciences in traditional settings in the UK, Jordan and Turkey. He is currently pursuing advanced studies in Jordan, where he is presently based with his family.