صحيح البخاري Sahih Bukhari كتاب التهجد The Book of Salat-Ut-Tahajjud (Night Prayer)
بَابُ مَا يُكْرَهُ مِنَ التَّشْدِيدِ فِي الْعِبَادَةِ:

(18) Chapter. It is disliked to exaggerate extremely in matters of worship.

2 hadith
Hadith 1150
حَدَّثَنَا أَبُو مَعْمَرٍ ، حَدَّثَنَا عَبْدُ الْوَارِثِ ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ صُهَيْبٍ ، عَنْ أَنَسِ بْنِ مَالِكٍ رَضِيَ اللَّهُ عَنْهُ , قَالَ : " دَخَلَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَإِذَا حَبْلٌ مَمْدُودٌ بَيْنَ السَّارِيَتَيْنِ , فَقَالَ : مَا هَذَا الْحَبْلُ ؟ , قَالُوا : هَذَا حَبْلٌ لِزَيْنَبَ فَإِذَا فَتَرَتْ تَعَلَّقَتْ ، فَقَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ : لَا حُلُّوهُ لِيُصَلِّ أَحَدُكُمْ نَشَاطَهُ فَإِذَا فَتَرَ فَلْيَقْعُدْ " .
Narrated Anas bin Malik Once the Prophet (p.b.u.h) entered the Mosque and saw a rope hanging in between its two pillars. He said, "What is this rope?" The people said, "This rope is for Zainab who, when she feels tired, holds it (to keep standing for the prayer.)" The Prophet said, "Don't use it. Remove the rope. You should pray as long as you feel active, and when you get tired, sit down."
Hadith Reference Sahih Bukhari / The Book of Salat-Ut-Tahajjud (Night Prayer) / Hadith: 1150
Hadith Grading محدثین: أحاديث صحيح البخاريّ كلّها صحيحة
Hadith 1151
وَقَالَ عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ , عَنْ مَالِكٍ ، عَنْ هِشَامِ بْنِ عُرْوَةَ ، عَنْ أَبِيهِ ، عَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا , قَالَتْ : " كَانَتْ عِنْدِي امْرَأَةٌ مِنْ بَنِي أَسَدٍ فَدَخَلَ عَلَيَّ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ : مَنْ هَذِهِ ؟ , قُلْتُ : فُلَانَةُ لَا تَنَامُ بِاللَّيْلِ فَذُكِرَ مِنْ صَلَاتِهَا ، فَقَالَ : مَهْ عَلَيْكُمْ مَا تُطِيقُونَ مِنَ الْأَعْمَالِ ، فَإِنَّ اللَّهَ لَا يَمَلُّ حَتَّى تَمَلُّوا " .
Narrated 'Aisha: A woman from the tribe of Bani Asad was sitting with me and Allah's Apostle (p.b.u.h) came to my house and said, "Who is this?" I said, "(She is) So and so. She does not sleep at night because she is engaged in prayer." The Prophet said disapprovingly: Do (good) deeds which is within your capacity as Allah never gets tired of giving rewards till you get tired of doing good deeds."
Hadith Reference Sahih Bukhari / The Book of Salat-Ut-Tahajjud (Night Prayer) / Hadith: 1151
Hadith Grading محدثین: أحاديث صحيح البخاريّ كلّها صحيحة