What is this? They said: It is for Zainab. She prays and when she slackens or feels tired she holds it. Upon this he (the Holy Prophet) said: Untie it. Let one pray as long as one feels fresh but when one slackens or becomes tired one must stop it. (And in the hadith transmitted by Zuhair it is:" He should sit down." )  

دَخَلَ رَسُولُ اللَّهِ ﷺ الْمَسْجِدَ وَحَبْلٌ مَمْدُودٌ بَيْنَ سَارِيَتَيْنِ فَقَالَ مَا هَذَا قَالُوا لِزَيْنَبَ تُصَلِّي فَإِذَا كَسِلَتْ أَوْ فَتَرَتْ أَمْسَكَتْ بِهِ فَقَالَ حُلُّوهُ لِيُصَلِّ أَحَدُكُمْ نَشَاطَهُ فَإِذَا كَسِلَ أَوْ فَتَرَ قَعَدَ وَفِي حَدِيثِ زُهَيْرٍ فَلْيَقْعُدْ  

A hadith like this has been narrated from the Messenger of Allah ﷺ on the authority of Anas by another chain of transmitters.  

عَنِ النَّبِيِّ ﷺ مِثْلَهُ  

It Is Haula' bint Tuwait and they say that she does not sleep at night. Upon this the Messenger of Allah ﷺ said: (Oh) she does not sleep at night! Choose an act which you are capable of doing (continuously). By Allah, Allah would not grow weary, but you will grow weary.  

أَنَّ عَائِشَةَ زَوْجَ النَّبِيِّ ﷺ أَخْبَرَتْهُ أَنَّ الْحَوْلاَءَ بِنْتَ تُوَيْتِ بْنِ حَبِيبِ بْنِ أَسَدِ بْنِ عَبْدِ الْعُزَّى مَرَّتْ بِهَا وَعِنْدَهَا رَسُولُ اللَّهِ ﷺ فَقُلْتُ هَذِهِ الْحَوْلاَءُ بِنْتُ تُوَيْتٍ وَزَعَمُوا أَنَّهَا لاَ تَنَامُ اللَّيْلَ فَقَالَ رَسُولُ اللَّهِ ﷺ لاَ تَنَامُ اللَّيْلَ خُذُوا مِنَ الْعَمَلِ مَا تُطِيقُونَ فَوَاللَّهِ لاَ يَسْأَمُ اللَّهُ حَتَّى تَسْأَمُوا  

The Messenger of Allah ﷺ came to me when a woman was sitting with me. He said: Who is she? I said: She is a woman who does not sleep but prays. He said: Do such acts which you are capable of doing. By Allah, Allah does not grow weary but you will grow weary. The religious act most pleasing to Him is one the doer of which does it continuously. (And in the hadith transmitted by Abu Usama [the words are]:" She was a woman from Banu Asad." )  

دَخَلَ عَلَىَّ رَسُولُ اللَّهِ ﷺ وَعِنْدِي امْرَأَةٌ فَقَالَ مَنْ هَذِهِ فَقُلْتُ امْرَأَةٌ لاَ تَنَامُ تُصَلِّي قَالَ عَلَيْكُمْ مِنَ الْعَمَلِ مَا تُطِيقُونَ فَوَاللَّهِ لاَ يَمَلُّ اللَّهُ حَتَّى تَمَلُّوا وَكَانَ أَحَبَّ الدِّينِ إِلَيْهِ مَا دَاوَمَ عَلَيْهِ صَاحِبُهُ وَفِي حَدِيثِ أَبِي أُسَامَةَ أَنَّهَا امْرَأَةٌ مِنْ بَنِي أَسَدٍ  

When anyone amongst you dozes in prayer, he should sleep, till sleep is gone, for when one of you prays while dozing he does not know whether he may be asking pardon or vilifying himself.  

أَنَّ النَّبِيَّ ﷺ قَالَ إِذَا نَعَسَ أَحَدُكُمْ فِي الصَّلاَةِ فَلْيَرْقُدْ حَتَّى يَذْهَبَ عَنْهُ النَّوْمُ فَإِنَّ أَحَدَكُمْ إِذَا صَلَّى وَهُوَ نَاعِسٌ لَعَلَّهُ يَذْهَبُ يَسْتَغْفِرُ فَيَسُبُّ نَفْسَهُ  

When any one of you gets up at night (for prayer) and his tongue falters in (the recitation) of the Qar'an, and he does not know what he is reciting, he should go to sleep.  

عَنْ مُحَمَّدٍ رَسُولِ اللَّهِ ﷺ فَذَكَرَ أَحَادِيثَ مِنْهَا وَقَالَ رَسُولُ اللَّهِ ﷺ إِذَا قَامَ أَحَدُكُمْ مِنَ اللَّيْلِ فَاسْتَعْجَمَ الْقُرْآنُ عَلَى لِسَانِهِ فَلَمْ يَدْرِ مَا يَقُولُ فَلْيَضْطَجِعْ