It was narrated that Usamah bin Sharik said: "I saw the Bedouins asking the Prophet 'Is there any harm in such and such, is there any harm in such and such?' He said to them: '0 slaves of Allah! Allah has only made harm in that which transgresses the honor of one's brother. That is what is sinful.' They said: '0 Messenger of Allah P.B.U.H Is there any sin if we do not seek treatment?' He said: 'Seek treatment, 0 slaves of Allah! For Allah does not create any disease but He also creates with it the cure, except for old age.' They said: '0 Messenger of Allah, what is the best thing that a person may be given?' He said: 'Good manners.": (Sahih)