[Sahih Bukhari : Volume 1, Book 11, Number 624]
Narrated Abu Huraira (Radi Allah Anhu): Allah’s Apostle (sal-allahu-alleihi-wasallam) said:
“While a man was going on a way, he saw a thorny branch and removed it from the way and Allah became pleased by his action and forgave him for that.”
Then the Prophet (sal-allahu-alleihi-wasallam) said, “Five are martyrs:
1. One who dies of plague,
2. One who dies of an abdominal disease,
3. One who dies of drowning,
4. One who is buried alive (and) dies
5. And One who is killed in Allah’s cause.”
The Prophet (sal-allahu-alleihi-wasallam) further said, “If the people knew the reward for pronouncing the Adhan and for standing in the first row (in the congregational prayer) and found no other way to get it except by drawing lots they would do so.
And if they knew the reward of offering the Zuhr prayer early (in its stated time), they would race for it.
And they knew the reward for ‘Isha’ and Fajr prayers in congregation, they would attend them even if they were to crawl’.”