We have developed a new product called Sajda Recorder. It is an electronic device that displays on its screen the number of rak’as and prostrations to help those who get confused or forget during prayers. Is it permissible to use it?
Yes, it is permissible to use this electronic device. This was precedent in the early generations of Muslims.
It was mentioned in Ibn Sa’ad’s al-Tabaqat and in al-Baladhuri’s Ansab al-Ashraf that Mohammed ibn Sirin said, “’Umar ibn al-Khattab (may God be pleased with him) had experienced forgetfulness during prayers, so he asked someone to stay behind him during prayer to remind him in case he forgets.”
Miswar ibn Yazid al-Asddi (may God be pleased with him) narrated, “I witnessed the Messenger of God (peace and blessings be upon him) in prayer and he forgot to recite some verses. After he ended the prayer, a man told him,‘O Messenger of God, you forgot such and such verses while reading. The Messenger replied, “You should have alerted me.”
Anas ibn malik (may God be pleased with him) narrated that the companions of the Messenger of God (peace and blessings be upon him) used to remind one another during prayers.
Anas ibn Malik also reported that when he started to pray, he used to have someone behind to remind him if he omitted any verses during recitation.
In his book Al-Mughni, Ibn Qudamada mentioned, “Amir ibn Rabi’ah said, “I was sitting in Mecca while a man was praying before the maqam, there was someone behind prompting him and it turned out to be ‘Uthman ibn Affan (may God be pleased with him).”