Supplication in bowing and prostration is permissible
13-1-2014 | IslamWeb
Question:
Can supplication in bowing and prostration invalidate prayer based on the Noble Quran and honorable Sunnah?
Answer:
All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Supplication in bowing and prostration does not invalidate prayer for it was reported that ‘Aa’ishah 
said: “The Messenger of Allaah, sallallaahu ‘alayhi wa sallam, often used to say when bowing and prostrating: Subhaanaka Allaahumma Rabbana wa bihamdika, Allaahumma ighfir li (i.e. Glory and praise be to You, O Allaah our Lord, O Allaah, Forgive me.)” [Al-Bukhari and Muslim]
Abu Hurayrah 
narrated: “The Messenger of Allaah, sallallaahu ‘alayhi wa sallam, used to say in his prostration: “Allaahumma ighfir li thanbi kullahu, diqqahu wa jillahu, wa awwalahu wa akhiraahu, wa alaniyatahu wa sirrahu (i.e. O Allaah! Forgive me all my sins, great and small, the first and the last, those that are apparent and those that are hidden).” [Muslim]
Abu Hurayrah also narrated that the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said: “The closest a person can be to his Lord is when he is prostrating so supplicate much (in it).” [Muslim]