Volume 1, Book 4, Number 141 :
Narrated by Usama bin Zaid
Allah's Apostle proceeded from 'Arafat till when he
reached the mountain pass, he dismounted, urinated and
then performed ablution but not a perfect one. I said to
him, ("Is it the time for) the prayer, O Allah's Apostle?" He
said, "The (place of) prayer is ahead of you." He rode till
when he reached Al-Muzdalifa, he dismounted and
performed ablution and a perfect one, The (call for)
Iqama was pronounced and he led the Maghrib prayer.
Then everybody made his camel kneel down at its place.
Then the Iqama was pronounced for the 'Isha' prayer
which the Prophet led and no prayer was offered in
between the two . prayers ('Isha' and Maghrib).