Answer
✅Answer: Please pay attention to the following narrations:
1 عَنْ عَلِيٍّ فِي حَدِيثِ الْأَرْبَعِمِائَةِ قَالَ: مَنْ كَانَ عَلَى يَقِينٍ فَشَكَّ فَلْيَمْضِ عَلَى يَقِينِهِ فَإِنَّ الشَّكَّ لَا يَنْقُضُ الْيَقِينَ
📚 Al-Khisal p. 619, hadith 629
Ali (peace be upon him) said in the 'Four Hundred Ahadith': One who is certain and then doubts, should proceed upon his certainty, for doubt does not break certainty!
2 عَنْ عِدَّةٍ مِنْ أَصْحَابِنَا عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنِ الْعَبَّاسِ بْنِ عَامِرٍ عَنْ عَبْدِ اللَّهِ بْنِ بُكَيْرٍ عَنْ أَبِيهِ قَالَ: قَالَ لِي أَبُو عَبْدِ اللَّه إِذَا اسْتَيْقَنْتَ أَنَّكَ قَدْ أَحْدَثْتَ فَتَوَضَّأْ وَ إِيَّاكَ أَنْ تُحْدِثَ وُضُوءاً أَبَداً حَتَّى تَسْتَيْقِنَ أَنَّكَ قَدْ أَحْدَثْتَ.
📚 Al-Kafi Vol. 3, p. 33
Bukayr said: Imam al-Sadiq (peace be upon him) said to me: When you are certain that a 'hadath' (something that invalidates ablution) has occurred from you, then perform ablution, and be careful not to renew your ablution until you are certain that something that invalidates ablution has occurred from you.
3 عَنْ عَبْدِ اللَّهِ بْنِ الْحَسَنِ عَنْ جَدِّهِ عَلِيِّ بْنِ جَعْفَرٍ عَنْ أَخِيهِ مُوسَى بْنِ جَعْفَرٍ قَالَ: سَأَلْتُهُ عَنْ رَجُلٍ يَتَّكِئُ فِي الْمَسْجِدِ فَلَا يَدْرِي نَامَ أَمْ لَا هَلْ عَلَيْهِ وُضُوءٌ قَالَ إِذَا شَكَّ فَلَيْسَ عَلَيْهِ وُضُوءٌ قَالَ وَ سَأَلْتُهُ عَنْ رَجُلٍ يَكُونُ فِي الصَّلَاةِ فَيَعْلَمُ أَنَّ رِيحاً قَدْ خَرَجَتْ فَلَا يَجِدُ رِيحَهَا وَ لَا يَسْمَعُ صَوْتَهَا قَالَ يُعِيدُ الْوُضُوءَ وَ الصَّلَاةَ وَ لَا يَعْتَدُّ بِشَيْ ءٍ مِمَّا صَلَّى إِذَا عَلِمَ ذَلِكَ يَقِيناً.
📚 Qurb al-Isnad p. 83
Ali ibn Ja'far said: I asked Imam al-Kazim (peace be upon him) about a person who leans against something in the mosque and does not know if he has fallen asleep or not. Is it obligatory for him to perform ablution? He said: If he has doubt, ablution is not obligatory for him!
And I asked him: A man is in prayer, then he becomes aware that he has passed gas, but he does not smell it and does not hear its sound. (What is his duty)?
He said: He should repeat the ablution and the prayer and not count the part of the prayer that he has performed, provided that he is certain of it (i.e., the passing of gas)!
4 عَنِ الْحُسَيْنِ بْنِ سَعِيدٍ عَنْ حَمَّادٍ عَنْ حَرِيزٍ عَنْ زُرَارَةَ قَالَ: قُلْتُ لَهُ الرَّجُلُ يَنَامُ وَ هُوَ عَلَى وُضُوءٍ أَ تُوجِبُ الْخَفْقَةُ وَ الْخَفْقَتَانِ عَلَيْهِ الْوُضُوءَ فَقَالَ يَا زُرَارَةُ قَدْ تَنَامُ الْعَيْنُ وَ لَا يَنَامُ الْقَلْبُ وَ الْأُذُنُ فَإِذَا نَامَتِ الْعَيْنُ وَ الْأُذُنُ وَ الْقَلْبُ وَجَبَ الْوُضُوءُ قُلْتُ فَإِنْ حُرِّكَ إِلَى جَنْبِهِ شَيْ ءٌ وَ لَمْ يَعْلَمْ بِهِ قَالَ لَا حَتَّى يَسْتَيْقِنَ أَنَّهُ قَدْ نَامَ حَتَّى يَجِي ءَ مِنْ ذَلِكَ أَمْرٌ بَيِّنٌ وَ إِلَّا فَإِنَّهُ عَلَى يَقِينٍ مِنْ وُضُوئِهِ وَ لَا تَنْقُضِ الْيَقِينَ أَبَداً بِالشَّكِّ وَ إِنَّمَا تَنْقُضُهُ بِيَقِينٍ آخَرَ.
📚 Al-Tahdhib Vol. 1, p. 8
Zurarah said: I said to the Imam (peace be upon him): A person who has ablution falls asleep. Does a single nap or two naps make ablution obligatory upon him?
The Imam said: O Zurarah! Sometimes the eye sleeps but the heart and ear do not. So when the eye, heart, and ear all sleep, ablution becomes obligatory!
I said: What about if something is moved beside him and he does not notice? He said: No (his ablution is not void) until he is certain that he has fallen asleep and a clear matter comes to him about it. Otherwise, he remains certain of his ablution, and never break certainty with doubt, for you only break it with another certainty!
✅ From the above narrations and others, it is clear that if a person is certain that he had ablution and then doubts whether his ablution has become void or not, he must remain on his certainty of having ablution and not pay attention to his doubt.
✅ According to the first and fourth narrations and the like, if a person is certain that he did not have ablution and now doubts whether he has performed ablution or not, he must remain on his certainty of not having ablution and perform ablution.
اللَّهُمَّ صَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ
وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ
doubt about ablution becoming void
doubt about performing ablution