مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 1244
Prayer
Moderation in what is done - Section 1
وَعَنْ أَنَسٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: " لِيُصَلِّ أَحَدُكُمْ نَشَاطَهُ وَإِذَا فَتَرَ فَلْيَقْعُدْ)
Anas reported God’s Messenger as saying, “One should pray as long as he is lively, but when he slackens he should stop.” (Bukhari and Muslim.)
Mishkat al-Masabih, 1244مُتَّفَقٌ عَلَيْهِ (الألباني)