Sheikh `Abd Allah b. Bayyah, professor at `Abd al-`Azîz University in Jeddah
These matters are considered by some scholars to be merely personal habits and nothing more.
Others scholars hold the view that the ways in which he carried out those practices are manners that we are encouraged to emulate when we carry out those same practices. According to this view, the way in which he used to use antimony in his eyes and the way in which he used to eat are recognized as Sunnah acts by Islamic Law.
This means that the actions themselves are merely personal habits, natural activities carried out by the Prophet (peace be upon him) in the sense that he is a human being. They are not matters of Islamic Law. However, when we look at the manners that he employed in carrying out those activities, we say that it is preferred for us to emulate him in those manners.
For instance, if one of us wants to use antimony in his eyes, then he should look at the way the Prophet (peace be upon him) used to use antimony and do so in the same manner. For instance, the Prophet (peace be upon him) used to apply it to his right eye before his left. However, men are not requested by Islamic Law to use antimony in the first place.
Scholars differ regarding some actions of the Prophet (peace be upon him) as to whether they fall into the category of natural activities and personal habits or into the category of prescribed acts of worship.
For example, the Prophet (peace be upon him) performed pilgrimage while riding. [Sahîh Muslim (1218)] Also, he would recline for a while after performing the two Sunnah units of the Fajr prayer before going to perform the Fajr prayer. [Sahîh al-Bukhârî (626) and Sahîh Muslim (736)]
In matters such as these, scholars have differed as to whether they are acts of worship to be emulated or merely personal practices of the Prophet (peace be upon him). Ahmad b. Hanbal held the view that they are preferable acts of worship. Mâlik held the view that they were merely personal habits.
In any event, the matter is an easy one. Whoever wishes to do these acts in emulation of the Prophet (peace be upon him), then it is good and well. Whoever refrains from doing these things, then there is nothing wrong with that.
And Allah knows best.
Source: Islam Today