(4) Prayer
كتاب الصلاة
(39c) Chapter: Prayer in the Forenoon - Section 3
(38) باب صلاة الضحى - الفصل الثالث
Mishkat al-Masabih 1320 
Abu Sa'id said:
God’s Messenger used to pray in the forenoon so often that we felt he would never stop doing so; then he would leave off doing so for so long that we felt he would never resume prayer at that time. Tirmidhi transmitted it.
وَعَنْ أَبِي سَعِيدٍ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُصَلِّي الضُّحَى حَتَّى نَقُولَ: لَا يَدَعُهَا وَيَدَعُهَا حَتَّى نَقُولَ: لَا يُصليهَا. رَوَاهُ التِّرْمِذِيّ
 ضَعِيف  (الألباني)حكم :
Reference : Mishkat al-Masabih 1320
In-book reference : Book 4, Hadith 729