If we forget the qunut in the second rak'ah of prayer and remember it in the bowing (ruku'), what should we do?

Answer:

مُحَمَّدُ بْنُ الْحَسَنِ بِإِسْنَادِهِ عَنِ الْحُسَیْنِ بْنِ سَعِیدٍ عَنْ فَضَالَةَ عَنْ جَمِیلِ بْنِ دَرَّاجٍ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ وَ زُرَارَةَ بْنِ أَعْیَنَ قَالَا سَأَلْنَا أَبَا جَعْفَرٍ عَنِ الرَّجُلِ یَنْسَی الْقُنُوتَ حَتَّی یَرْکَعَ قَالَ یَقْنُتُ بَعْدَ الرُّکُوعِ فَإِنْ لَمْ یَذْکُرْ فَلَا شَیْ ءَ عَلَیْهِ

Tahdhib, vol. 2, p. 160

Translation: Zurarah and Muhammad ibn Muslim said: We asked Imam Baqir, peace be upon him, about a person who forgets the qunut until he goes into ruku'. The Imam said: 'He should perform the qunut after ruku', and if he does not remember (that he had left the qunut), there is nothing on him.'

The above narration is for a case where a person remembers in ruku' that he left the qunut, but if he remembers it after that, the following two hadiths are to be followed:

مُحَمَّدُ بْنُ یَعْقُوبَ عَنْ مُحَمَّدِ بْنِ إِسْمَاعِیلَ عَنِ الْفَضْلِ بْنِ شَاذَانَ عَنْ حَمَّادِ بْنِ عِیسَی عَنْ حَرِیزٍ عَنْ زُرَارَةَ قَالَ قُلْتُ لِأَبِی جَعْفَرٍ رَجُلٌ نَسِیَ الْقُنُوتَ (فَذَکَرَهُ) وَ هُوَ فِی بَعْضِ الطَّرِیقِ فَقَالَ یَسْتَقْبِلُ الْقِبْلَةَ ثُمَّ لْیَقُلْهُ ثُمَّ قَالَ إِنِّی لَأَکْرَهُ لِلرَّجُلِ أَنْ یَرْغَبَ عَنْ سُنَّةِ رَسُولِ اللَّهِ( صلی الله علیه و آله) أَوْ یَدَعَهَا

Kafi, vol. 3, p. 340

Translation: Zurarah said: I said to Imam Baqir, peace be upon him: 'A person forgets the qunut and then remembers it when he is on his way (after the prayer).' The Imam said: 'He should face the qiblah and say the qunut (right there).' Then the Imam said: 'I dislike and find it reprehensible for a person to be apathetic about the Sunnah of the Messenger of Allah, peace and blessings be upon him and his family, or to abandon it.'

بِإِسْنَادِهِ عَنْ أَحْمَدَ بْنِ مُحَمَّدِ بْنِ عِیسَی عَنْ عَلِیِّ بْنِ الْحَکَمِ عَنْ أَبِی أَیُّوبَ عَنْ أَبِی بَصِیرٍ قَالَ سَمِعْتُهُ یَذْکُرُ عِنْدَ أَبِی عَبْدِ اللَّهِ قَالَ فِی الرَّجُلِ إِذَا سَهَا فِی الْقُنُوتِ قَنَتَ بَعْدَ مَا یَنْصَرِفُ وَ هُوَ جَالِسٌ

Tahdhib, vol. 2, p. 161

Translation: Imam Sadiq, peace be upon him, said about a man who makes an error in qunut (forgets qunut unintentionally): 'After he has said the salam of the prayer, he should perform the qunut while he is sitting.'

From the three hadiths above, it is clear that if a person forgets the qunut and remembers it while in ruku' and before going to prostration, he should perform the qunut after raising his head from ruku' and standing, before going to prostration. If he remembers it after ruku' until the end of the prayer, he should perform the qunut after the prayer while sitting. And if he remembers it after these times, wherever he is, he should face the qiblah and perform the qunut.