of bed-sickness, provided that an essoin of difficulty in coming has come first, and  so and in the same way, as said above, until all together, or some or one alone has  languor. After the essoin returned and the day certain (if it is passing illness)  accepted, the demandant ought at once and without delay to cause a writ .for  viewing the essoinee1 to issue to the sheriff.2
Of the duty of the sheriff when he has received the writ.
 The duty of the sheriff, when he receives the writ in the county court, is to send  four lawful knights at once to view the essoinee. He ought to take for this purpose  knights who are present and not summon knights who are absent, because of the  words of the writ: Send four [of your county].3 It does not suffice if he sends serjeants,  for they ought to be knights, because of the words of the writ: Send  knights. It does not suffice to send three, because of the words of the writ: Send  four, and because where a fixed number is specified, namely four, two or three are  not sufficient.4 Nor does it suffice if two or three assume companions to make up the  four, because they ought not to view or testify unless they are sent. Of his county,  is said5 for this reason, because if he wished to send others he would not have coercion.  It is said to such a place, because if the essoinee should not be found in the  place named in the essoin he could thus be in default, [and so] if he had not kept  himself in languor in the proper way. It is also said to see whether the infirmity  etc. For they must view his body and inquire diligently as to the kind of infirmity  and the circumstances, and accordingly award passing illness or languor, (and  give the reason therefor if they are asked,) and give him a day certain in court or  at the Tower of London. It is given at the Tower because it is a place certain, where  the constable ought always to be present, who ought to attest the day of their  appearance and arrival, and because the justices are not always resident in the  Bench continuously throughout the year. When a day is thus given the parties at  the Tower, after the year and day it does not suffice if the parties, neglecting that  place, come before the justices at Westminster, if they are then resident there, because  it is one thing to give a day at the Tower and another to give it at Westminster  in the Bench. Thus when they have had a day at the Tower, they ought to  receive a day in the Bench from the constable at the Tower, if the justices are then  resident in the Bench, or if they are not, when they next come, unless they are then  itinerant in the county,6 because then a day will be given there,