بسم اللہ الرحمٰن الرحیم

الجواب وباللہ التوفیق: 

For each rak'ah of Taraweeh and other Sunan and Nawafil prayers, a single long verse equivalent to at least the below three short verses of the Holy Qur'an is the minimum obligatory (wajib) length of recitation to validate a salah 

ثُـمَّ نَظَرَ ، ثُـمَّ عَبَسَ وَبَسَرَ ، ثُـمَّ اَدْبَـرَ وَاسْتَكْـبَـرَ 

 (المد ثر آیۃ ۲۱؍۲۲؍۲۳)

It is “wajib” to repeat the prayer by intentionally abandoning that much recitation from the Holy Qur’an 

If the Imam had bowed down in “rukoo’a” after reciting a single verse of Surah Baqarah, the length of which was at least equal to above three small verses, then his prayer was valid. But if that single verse was shorter than the minimum limit, then it becomes “wajib” to repeat that prayer 

If due to lack of knowledge or unintentional ignorance, the verse recited by the Imam was shorter than the required minimum, then there is no need to repeat it. However, it is important to make Imam Sahib aware of the Shari’ah rule so that he is careful in future

The narration regarding the tradition of Ibn Abbas (RA), is considered weak. In fact, one of its narrators, Sahl bin Amir al-Bajli, has been declared a denier of hadith by Imam Bukhari (RA) 

The imams specialized in the cross-examination and categorization of “Ahadith” have labeled this a fabricated narration

The second answer is that it is an abandoned narration, meaning that it is the personal action of Ibn Abbas (RA), which is indefensible when comparing it with genuine traditions, which enforce the necessity of longer recitation

The third answer is that if the reasoning is based on the ‘Aayah”

فاقروا ما تیسر من القرآن

as Ibn Abbas (RA) has done, So, by what argument is Surah Fatiha and one verse being appropriated and limited? Then even reading less than that limit should make the prayer correct. Therefore, it is not correct to justify such a reasoning based on that  tradition

قال الجوہر النقی کیف یکون اسنادا حسنا  وفیہ سہل بن عامر البجلی۔ قال ابو حاتم الرازی کان یفتعل الحدیث، وقال البکار منکر الحدیث ،وفی لسان المیزان ولفظ ابی ھاتم فیما نقلہ ابنہ ضعیف الحدیث۔روی لنا احادیث بواطیل ادرکتہ بالکوفۃ وکان یفتعل الحدیث وذکرہ ابن حبان فی الثقات ۔قلت لا یقبل التوثیق اذا کان الجرح مفسرا لا سیما اذا جرح بالوضع علی انہ بعد صحتہ یدل علی عدم رکنیۃ  السورۃ ونحن قائلون بہ فلاحجۃ بہ علینا۔(اعلاء السنن ۲/۲۴۰)

) ولها واجبات) لاتفسد بتركها وتعاد وجوبًا في العمد -  

الدر المختار وحاشية ابن عابدين (رد المحتار: ۱/۴۵۶) 

وضم اقصر سورۃ کالکوثر او قام مقامھا ھو ثلاث آیات قصار نحو ثم نظر (المدثر:۲۱)

وکذا لو کانت الآیۃ او الا یتان تعدل ثلاثاً قصارا ذکرہ الحلبی ۔اھ (الدر المختار وحاشیہ ابن عابدین:۱؍۴۵۸)

 وکذا لو کانت الآیۃ او الا یتان تعدل ثلاثاً قصارا ذکرہ الحلبی ۔اھ (الدر المختار وحاشیہ ابن عابدین:۱؍۴۵۸)

والمختار أن المعادة؛ لترك واجب نفل جابر، والفرض سقط بالأولى؛ لأن الفرض لا يتكرر، كما في الدر وغيره". (١/ ٢٤٨،ط:دار الكتب العلمية بيروت)

فقط واللہ اعلم بالصواب