✅ Answer: Please pay attention to the following narrations:

1 عن حبیب الخثعمی قال: شَکَوْتُ إِلَی أَبی عبداللَّه کَثْرَةَ السَّهْوِ فی الصَّلَاةِ فقال أَحْصِ صَلَاتَکَ بِالْحَصَی أَوْ قال احْفَظْهَا بِالْحَصَی

📚 Tahdhib, Vol. 2, p. 348

Habib al-Khath'ami said: 'I complained to Imam Sadiq (peace be upon him) about making many mistakes in prayer.' The Imam said: 'Count your prayer with pebbles!' Or he said: 'Keep track of it with pebbles!'

2 عن حبیب بن الْمُعَلَّی أَنَّهُ سَأَلَ أَباعبداللَّه فقال لَهُ إِنِّی رَجُلٌ کَثِیرُ السَّهْوِ فَمَا أَحْفَظُ صَلَاتِی إِلَّا بِخَاتَمِی أُحَوِّلُهُ مِنْ مَکَانٍ إِلَی مَکَانٍ فَقَالَ لَا بَأْسَ بِهِ

📚 Faqih, Vol. 1, p. 255

Habib ibn Mu'alla asked Imam Sadiq (peace be upon him) and said: 'I am a person who makes a lot of mistakes and I cannot keep track of my prayer except by moving my ring from one place to another!' The Imam said: 'There is no objection!'

3 فی رِوَایَةِ عبداللَّهِ بْنِ الْمُغِیرَةِ أَنَّهُ قال لَا بَأْسَ أَنْ یَعُدَّ الرَّجُلُ صَلَاتَهُ بِخَاتَمِهِ أَوْ بِحَصًی یَأْخُذُ بِیَدِهِ فَیَعُدُّ بِهِ

📚 Faqih, Vol. 1, p. 339

In the narration of Abdullah ibn Mughirah, it is said that the Imam (peace be upon him) said: 'There is no objection for a person to count the rak'ahs of his prayer with his ring or to hold pebbles in his hand and count his prayer with them!'

4 كَتَبَ الْحِمْيَرِيُّ إِلى الْقَائِمِ هَلْ يَجُوزُ لِلرَّجُلِ إِذَا صَلَّى الْفَرِيضَةَ أَوِ النَّافِلَةَ وَ بِيَدِهِ السُّبْحَةُ أَنْ يُدِيرَهَا و هُوَ في الصَّلَاةِ فَأَجَابَ يَجُوزُ ذَلِكَ إِذَا خَافَ السَّهْوَ و الْغَلَطَ

📚 Al-Ihtijaj, p. 490

Al-Himyeri wrote to Imam Mahdi (peace be upon him): 'Is it permissible for a person, when he is performing a mandatory or supererogatory prayer and has a rosary in his hand, to turn it during the prayer?' The Imam replied: 'It is permissible if he fears making a mistake or error!'

5 عن الفضیل قال: ذَکَرْتُ لِأَبی عبداللَّه السَّهْوَ فقال وَ یَنْفَلِتُ مِنْ ذَلِکَ أَحَدٌ رُبَّمَا أَقْعَدْتُ الْخَادِمَ خَلْفِی یَحْفَظُ عَلَیَّ صَلَاتِی

📚 Mustatrafat al-Sara'ir, p. 110

Fudayl said: 'I mentioned making mistakes (in prayer) to Imam Sadiq (peace be upon him).' The Imam said: 'Does anyone escape from it?! Sometimes I have a servant stand behind me to keep track of my prayer for me!' (Of course, considering other narrations, this was certainly not due to the Imam making mistakes in prayer, and we can only infer the permissibility of this act for ourselves.)

6 قال الصَّادِقُ کُلُّ شَیْءٍ مُطْلَقٌ حَتَّی یَرِدَ فِیهِ نَهْیٌ

📚 Faqih, Vol. 1, p. 317

Imam Sadiq (peace be upon him) said: 'Everything is absolute unless a prohibition has been mentioned for it!'

✅ In the above narrations, it can be seen that for those who make a lot of mistakes in prayer, several ways to avoid mistakes have been permitted:

1. Counting the rak'ahs of prayer with pebbles that he holds in his hand, for example, each time he prostrates, he puts one on the ground or transfers one of the pebbles to his other hand after each rak'ah, and so on, so that he knows how many rak'ahs he has prayed and which rak'ah he is in now.

2. Counting the rak'ahs of prayer by changing the location of a ring. For example, the first rak'ah is on the little finger, and with each rak'ah, he moves it to the next finger, and so on, so that he knows which rak'ah of the prayer he is in now.

3. Holding a rosary in hand and turning it during the prayer to keep track of the number of rak'ahs and save oneself from mistakes and errors.

4. Counting the rak'ahs by having someone we have assigned stand behind us and count the rak'ahs of our prayer so that we do not make mistakes.

✅ As stated in most of the above narrations, the four mentioned cases are generally for individuals who make many mistakes in prayer, and they are allowed to use these methods to save themselves from mistakes. Therefore, it is better and safer to use them only for individuals who make a lot of mistakes in prayer.

✅ Although no specific hadith has been transmitted for today's prostration counters, considering the general principle stated in hadith 6 and others, due to the lack of a specific or general prohibition for its use, individuals who make many mistakes can use it to keep track of their rak'ahs and avoid mistakes in prayer.

✅ An important point is that today's prostration counters are designed in a way that can prevent the nose from touching the prayer stone (mohr). According to the command of the Ahl al-Bayt (peace be upon them) in this regard, it must be used in a way that does not prevent this Sunnah from being performed.

In the following link, you can see the importance of the nose touching what the forehead touches:

https://feghh14.com/en/538