✅ Answer: Refer to the following narrations:

1⃣عَنِ الْفُضَیْلِ بْنِ یَسَارٍ أَنَّهُ سَأَلَ أَبَا عَبْدِ اللَّهِ عَنِ السَّهْوِ فَقَالَ مَنْ حَفِظَ سَهْوَهُ فَأَتَمَّهُ فَلَیْسَ عَلَیْهِ سَجْدَتَا السَّهْوِ وَ إِنَّمَا السَّهْوُ عَلَی مَنْ لَمْ یَدْرِ أَ زَادَ فِی صَلَاتِهِ أَمْ نَقَصَ مِنْهَا.

📚 *Al-Faqih*, Vol. 1, p. 350

Fudayl ibn Yasar asked Imam Sadiq (peace be upon him) about mistakes in prayer. The Imam said: One who recognizes and rectifies their mistake does not need to perform the prostration of forgetfulness. Forgetfulness applies to those who do not know if they have added or omitted from their prayer.

2⃣عَنْ سَعْدٍ عَنْ أَیُّوبَ بْنِ نُوحٍ عَنْ عَلِیِّ بْنِ النُّعْمَانِ الرَّازِیِّ عَنْ أَبِی عَبْدِ اللَّهِ فِی حَدِیثٍ قَالَ: إِنَّمَا یُعِیدُ مَنْ لَمْ یَدْرِ مَا صَلَّی.

📚 *Tahdhib*, Vol. 2, p. 181

Imam Sadiq (peace be upon him) said: Only those who do not know how much of their prayer they have performed must repeat their prayer.

3⃣عَنْ حَمْزَةَ بْنِ حُمْرَانَ عَنْ أَبِی عَبْدِ اللَّهِ قَالَ: مَا أَعَادَ الصَّلَاةَ فَقِیهٌ قَطُّ یَحْتَالُ لَهَا وَ یُدَبِّرُهَا حَتَّی لَا یُعِیدَهَا.

📚 *Tahdhib*, Vol. 2, p. 351

Imam Sadiq (peace be upon him) said: A knowledgeable person does not repeat their prayer. They resolve (the issue) through jurisprudential reasoning to avoid repeating it.

4⃣عَنِ الْأَعْمَشِ عَنْ جَعْفَرِ بْنِ مُحَمَّدٍ فِی حَدِیثِ شَرَائِعِ الدِّینِ قَالَ: وَ مَنْ لَمْ یُقَصِّرْ فِی السَّفَرِ لَمْ تُجْزِ صَلَاتُهُ لِأَنَّهُ قَدْ زَادَ فِی فَرْضِ اللَّهِ عَزَّ وَ جَلَّ.

📚 *Al-Khisal*, p. 604

In the narration of *Sharai al-Din*, Imam Sadiq (peace be upon him) said: Whoever deliberately does not shorten their prayer while traveling, their prayer is invalid because they have added to the divine obligation.

✅ Based on the above narrations and others, a traveler intending to stay less than ten days must pray a shortened prayer. If they mistakenly intended a four-unit prayer but realized their mistake before exceeding two units and completed it as a two-unit prayer, the rulings of forgetfulness and even the prostration of forgetfulness do not apply, and there is no need to repeat the prayer.

However, if they added one or two units to the prayer due to this mistake and realized it afterward, they must repeat the prayer.

✅ If they mistakenly prayed four units and realized the error after the prayer time had passed, there is no need to repeat the prayer. For related narrations, see the link below:

https://t.me/porseshvapasokhe/783

اللَّهُمَّ صَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْر

https://t.me/porseshvapasokhe