Chapter on the Rulings of Congregational Prayer (the Minimum Number for Congregational Prayer, the Description of the Imam, Who Is to Be Followed and Who Is Not to Be Followed, Recitation Behind Both of Them, the Rulings of Those Led in Prayer, and Other Such Rulings Related to It)

Tahdhīb al-Aḥkām|Volume 3|Book 1|Chapter 3

Tahdhīb al-Aḥkām

Volume 3, Book 1, Chapter 3

Chapter on the Rulings of Congregational Prayer (the Minimum Number for Congregational Prayer, the Description of the Imam, Who Is to Be Followed and Who Is Not to Be Followed, Recitation Behind Both of Them, the Rulings of Those Led in Prayer, and Other Such Rulings Related to It)

Hadith #2

أَحْمَدُ بْنُ مُحَمَّدِ بْنِ عِيسَى عَنْ عَلِيِّ بْنِ أَحْمَدَ بْنِ أَشْيَمَ عَنِ اَلْحُسَيْنِ بْنِ يَسَارٍ اَلْمَدَائِنِيِّ: أَنَّهُ سَمِعَ مَنْ يَسْأَلُ اَلرِّضَا عَلَيْهِ اَلسَّلاَمُ عَنْ رَجُلٍ صَلَّى إِلَى جَانِبِ رَجُلٍ فَقَامَ عَنْ يَسَارِهِ وَ هُوَ لاَ يَعْلَمُ كَيْفَ يَصْنَعُ ثُمَّ عَلِمَ هُوَ وَ هُوَ فِي اَلصَّلاَةِ قَالَ« يُحَوِّلُهُ عَنْ يَمِينِهِ»

Ahmad ibn Muhammad ibn Isa from Ali ibn Ahmad ibn Ashyam from al-Husayn ibn Yasar al-Mada’ini: He (al-Mada’ini) heard someone ask Imam al-Ridha , peace be upon him, about a man who prayed beside another man and stood to his left without knowing what to do then he realized (the mistake) while still in the prayer. Imam , peace be upon him, said: “He should move him to his right.”

Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 3, p. 29