Abdullah bin Burayda bin al-Husayb عبد الله بن بريدة بن الحصيب الأسلمي · The Book on Salat (Prayer)

the Prophet said: "Between every two calls (to prayer) there is a Salat for whoever wills."

"Allah's Messenger would recite: By the sun and its brightness, or similar Surah for the latter Isha (prayer)."

"I asked Allah's Messenger (S) about the Salat for a man who is sitting. He said: 'Whoever performs Salat while standing then that is more virtuous. And whoever performs Salat while sitting, then he gets half the rewards of the one standing, and whoever performs Salat while lying down, then he gets half the rewards of the one sitting.'"