It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that a man who intended to travel came to the Prophet (peace and blessings be upon him) and said: "O Messenger of Allah! Give me advice." He (peace and blessings be upon him) said: "I advise you to have taqwa (fear) of Allah and to say Allahu Akbar on every high place." Then, when the man had gone, he (peace and blessings be upon him) supplicated: 'Allahumma azwi lahu al-arda, wa hawwin 'alayhi al-safar' (O Allah, fold up the earth for him and make the journey easy for him). This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it.