Shama-il Tirmidhi Chapter 36, Hadith Number 1 (231).
(That means if one wants to know anything about a place, one will have to pay a person for obtaining information. A person has to be given money etc., for the journey in order to obtain information. At times it may so happen that the news is received without having to spend anything. Someone comes and gives full news. Some of the ulama have written that this example given by Sayyidina Rasoolullah sallallahu alaihe wasallam, that without any remuneration, he has given (humanity) the news of Jannah, Jahannum, Qiyaamah, particulars and information regarding the Ambiyaa alaihis salaam, the signs of the future etc. Yet the kuffar (non-believers) do not appreciate this. In this hadith two poets are mentioned, Sayyidina Abdullah ibn Rawahah radiyallahu anhu a famous Sahaabi who accepted Islam before the Hijrah of Sayyidina Rasoolullah sallallahu alaihe wasallam in the Battle of Mu’ata. The second poet is Tarfah, a famous poet of Arabia. In the famous book of Arabic literature ‘Sab’ah Mu’allaqah’, the second Mu’allaqah has been written by him. He lived before the advent of Islam.)