Hadith no. 2636 (below) is a repeat. Read it here.
Volume 4, Book 52, Number 240 :
Narrated by Jabir bin ‘Abdullah (radiallaahu `anhu)
On the day of the battle of the Trench, the Prophet (sallallaahu `alayhi wasallam) wanted somebody from amongst the people to volunteer to be a reconnoiter. Az-Zubair (radiallaahu `anhu) volunteered. He demanded the same again and Az-Zubair (radiallaahu `anhu) volunteered again. Then he repeated the same demand (thrice) and Az-Zubair (radiallaahu `anhu) volunteered once more. The Prophet (sallallaahu `alayhi wasallam) then said, ” Every prophet has a disciple and my disciple is Az-Zubair.”
Volume 4, Book 52, Number 241 :
Narrated by Ibn’ Umar (radiallaahu `anhu)
From the Prophet (sallallaahu `alayhi wasallam) the following Hadith (No. 242).
Volume 4, Book 52, Number 242 :
Narrated by Ibn ‘Umar (radiallaahu `anhu)
The Prophet (sallallaahu `alayhi wasallam) said, “If the people knew what I know about traveling alone, then nobody would travel alone at night.”
Imam Ahmad was asked about a man spending the night alone. He said: I prefer him to avoid that. Quoted from al-Adaab al-Shar’iyyah (1/428).
It was narrated from ‘Abd-Allaah ibn ‘Amr ibn al-‘Aas that the Prophet (peace and blessings of Allaah be upon him) said: “The (lone) rider is a devil, two riders are two devils and three are a travelling party.” Narrated by al-Tirmidhi (1674), who said it is a hasan hadeeth. It was also classed as hasan by Ibn Hajar in Fath al-Baari (6/53) and by al-Albaani in al-Silsilah al-Saheehah (62).
These ahaadeeth indicate that it is makrooh to be alone in situations where a man fears for himself because of weakness, severe exhaustion or hardship, or when he fears that the shaytaan may tempt him and mislead him. The benefit of being with righteous companions is not limited to help and support, rather the most important thing is that it helps him to remain steadfast and pious, for the shaytaan is further away from two.
Al-Haafiz Ibn Hajar said in Fath al-Baari (6/53):
Ibn Khuzaymah reported it under the heading; “the prohibition on two travelling and that less than three are sinners,” because what is meant by “devil” is a sinner. Al-Tabari said: This is a rebuke aimed at disciplining and guiding because of the fear of loneliness for one, but it is not haraam. The one who travels alone in the wilderness and the one who stays alone in a house has no guarantee that he will not feel lonely, especially if he had bad thoughts and is weak in faith.
In fact people differ with regard to that and the prohibition concerning that is a measure of protection, but if there is need for that, it should be fine. It was said, commenting on the words “the (lone) rider is a devil” that his travelling alone is suggested to him by the shaytaan, or he is likened to the shaytaan in his actions. And it was said that it is disliked because if the person who is travelling alone dies on the journey, there will be no one who can take care of him; similarly, if two are travelling and both or one die, there will be no one to help, unlike three, because in most cases that fear will not be present. End quote.
The apparent meaning of the hadeeth is that the prohibition applies to the one who travels alone via empty and remote routes. As for well-travelled routes, and those in which there is no risk of being lost, and where there are likely to be helpers and companions, there is no report that it is makrooh or prohibited. The same applies to travelling nowadays on planes, ships and buses, because those who are in them are all regarded as traveling companions, so the one who travels by these means is not alone in the sense that is forbidden.
Shaykh Ibn ‘Uthaymeen said in Fataawa Noor ‘ala al-Darb (mutafarraqaat/al-adaab):
This points to the warning against travelling alone, but that applies to journeys where the route is not travelled by many. As for journeys where the route is travelled by many, and it is as if one is in the middle of a village, such as the route from al-Qaseem to Riyadh, or Riyadh to Dammam and other such routes where there are many travellers, and the road to the Hijaz during the Hajj season, this is not in fact regarded as being alone, because many people travel by these routes. So a person may be alone in his car but he is not alone on the journey, rather there are people around him, behind him and in front of him at every moment. End quote.
Shaykh al-Albaani said in his commentary on this hadeeth in al-Saheehah (62):
Perhaps the hadeeth refers to travelling in the deserts or wilderness where the traveller rarely sees anyone. It does not include travel nowadays on paved and well-travelled roads. And Allaah knows best. End quote.
Taken from IslamQA
Volume 4, Book 52, Number 243 :
Narrated by Hisham’s father
Usama bin Zaid (radiallaahu `anhu) was asked at what pace the Prophet (sallallaahu `alayhi wasallam) rode during Hajjat-ul-Wada’ “He rode at a medium pace, but when he came upon an open way he would go at full pace.”
Volume 4, Book 52, Number 244 :
Narrated by Aslam
While I was in the company of ‘Abdullah bin ‘Umar (radiallaahu `anhu) on the way to Mecca, he received the news of the severe illness of Safiya bint Abi Ubaid (i.e. his wife), so he proceeded at greater speed, and when the twilight disappeared, he dismounted and offered the Maghrib and ‘Isha ‘prayers together and said, “I saw the Prophet (sallallaahu `alayhi wasallam) delaying the Maghrib prayer to offer it along with the ‘Isha’ when he was in a hurry on a journey.”
Volume 4, Book 52, Number 245 :
Narrated by Abu Huraira (radiallaahu `anhu)
Allah’s Apostle (sallallaahu `alayhi wasallam) said, “Journey is a piece of torture, for it disturbs one’s sleep, eating and drinking. So, when you fulfill your job, you should hurry up to your family.”