(3) باب كَيْفَ فُرِضَتِ الصَّلاَةُ .
It was narrated that 'Aishah said:
"The first time the Salah was enjoined it was two Rak'ahs, and it remained as such when traveling, but the Salah while resident was made complete." (ES)
Reference (ES): Sunan an-Nasa'i 453 (ES)
In-book reference (ES): Book 5, Hadith 6 (ES)
English translation (ES): Vol. 1, Book 5, Hadith 454 (ES)