Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Sahl bin Hanzaliyah (may Allah be pleased with him) that on the day of Hunayn, the companions were walking with the Messenger of Allah (peace and blessings of Allah be upon him), and they kept walking for a long time until evening came. The time for prayer arrived. A horseman came and said: O Messenger of Allah! I kept riding ahead of you and crossed such-and-such mountains, until early morning I reached the Hawazin tribe. Their elders, along with their wives, camels, and sheep, are gathered in Hunayn. The Messenger of Allah (peace and blessings of Allah be upon him) smiled and said: "This wealth is going to become the booty of the Muslims tomorrow, insha’Allah." Then he said: "Who will keep watch tonight?" Anas bin Abu Marthad Ghanawi said: O Messenger of Allah! I will. The Prophet (peace and blessings of Allah be upon him) said: "Mount your horse." He mounted his horse and came to the Messenger of Allah (peace and blessings of Allah be upon him). The Messenger of Allah (peace and blessings of Allah be upon him) said: "Go towards this pass and reach its highest peak. Tonight, we should not be deceived from your direction." When morning came, the Messenger of Allah (peace and blessings of Allah be upon him) went out to the place of prayer, prayed two rak‘ahs of Sunnah, and asked: "Did you notice your horseman?" They said: O Messenger of Allah! We did not notice him. Then the iqamah was given, the Messenger of Allah (peace and blessings of Allah be upon him) began the prayer, and during the prayer, he kept turning towards that pass until he completed the prayer and said salam. Then he said: "Rejoice, your horseman has come." We began to look between the trees of the pass. Suddenly, he arrived, stood before the Messenger of Allah (peace and blessings of Allah be upon him), greeted him, and said: According to the command of the Messenger of Allah (peace and blessings of Allah be upon him), I went and reached the top of the valley. When morning came, I crossed two passes, but I did not see any man. The Messenger of Allah (peace and blessings of Allah be upon him) asked him: "Did you dismount your ride at night?" He said: No, except to pray or to relieve myself. The Messenger of Allah (peace and blessings of Allah be upon him) said to him: "You have made Paradise obligatory for yourself; after today, even if you do not do any (further) deeds, there is no harm."