Abd al-Rahman bin Shimasah relates that Sayyiduna Amr bin al-As (may Allah be pleased with him) led the people in prayer, and he stood up (forgetfully) instead of sitting for the (first) tashahhud. The people called out to him loudly to alert him, saying: 'Subhan Allah, Subhan Allah' (Glory be to Allah, Glory be to Allah), but he remained as he was and continued the prayer. When he had completed his prayer, he made two prostrations (of forgetfulness), then said: "O people, what you wanted to point out to me was not hidden from me, and nothing prevented me from sitting (for the tashahhud) except what I did in following the Sunnah (that after rising to standing one does not go back)."
It is also narrated from Abd al-Rahman bin Shimasah that Sayyiduna Uqbah bin Amir (may Allah be pleased with him) likewise stood up in his prayer (leaving the tashahhud), and then the narrator mentioned an incident similar to it.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب النوافل / 667
Hadith Gradingمحدثین:إسناده صحيح
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسناد صحيح جداً على شرط الإمام مسلم؛ رجاله أئمة ثقات متصلو السماع. » «انفرد به المصنف من هذا الطريق»