(13) باب اسْتِحْبَابِ صَلاَةِ الضُّحَى وَأَنَّ أَقَلَّهَا رَكْعَتَانِ وَأَكْمَلَهَا ثَمَانِ رَكَعَاتٍ وَأَوْسَطَهَا أَرْبَعُ رَكَعَاتٍ أَوْ سِتٌّ وَالْحَثِّ عَلَى الْمُحَافَظَةِ عَلَيْهَا
'Abdullah b. Shaqiq reported:
I aksed 'A'isha whether the Messenger of Allah (ﷺ) used to observe the forenoon prayer. She said: No, except when he came back from a journey.
Reference: Sahih Muslim 717 b
In-book reference: Book 6, Hadith 91
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 1547