Muwatta Imam Malik (Riwayat Ibn al-Qasim)

It is narrated from Abdullah bin Abdur Rahman bin Abi Sa’sa’ah Al-Ansari Al-Mazini (may Allah have mercy on him) that Sayyiduna Abu Sa’id Al-Khudri (may Allah be pleased with him) said to him: I see that you like sheep and the wilderness, so if you are among your sheep or in the wilderness and you call the adhan for prayer, then raise your voice, for whatever hears the voice of the muezzin—whether jinn, human, or anything else—will bear witness for him on the Day of Resurrection. Abu Sa’id Al-Khudri (may Allah be pleased with him) said: I heard this from the Messenger of Allah (peace and blessings be upon him).

And with this same chain (it is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him) that the Messenger of Allah, peace and blessings be upon him, said: "A man was walking on a path when he saw a thorny branch on the road, so he removed it from the path. Allah appreciated this and forgave him." And the Prophet, peace and blessings be upon him, said: "There are five types of martyrs: the one who dies of plague, the one who dies of a stomach illness, the one who drowns, the one who dies under a collapsed building, and the one who is martyred in the way of Allah." And the Prophet, peace and blessings be upon him, said: "If people knew what (reward) is in the call to prayer and the first row, and they had no way except to draw lots, they would draw lots. And if they knew how much (reward) there is in coming early to the noon prayer, they would compete with each other to get ahead. And if they knew what (reward) is in the night and morning prayers, they would surely come, even if they had to crawl on their knees."