he can never vouch his own feoffor to warranty with respect to his own act and incumbrance.
One is not bound with respect to his tenant's incumbrance.
 Suppose that with respect to his own act and incumbrance one has vouched his feoffor  to warranty and he has warranted and given escambium; how and by what writ ought  the escambium to be recalled? For example, A. enfeoffs B., B. enfeoffs C., the paternal  aunt of D.; on C.'s death, D. brings the assise against B. the chief lord who enfeoffed  C.; B. vouches A. to warranty and A. comes and warrants; D. recovers his seisin  against A.; A. gives escambium to the value to B. At the complaint of A. the escambium  will be returned to him by this writ:
Of the recovery of escambium where it has been given.
 The king to the sheriff, greeting. We order you to cause B. to come before etc. on such  a date, 1 to answer A. as to why he took escambium from A.'s land to the value of so  much land with the appurtenances in such a vill, which D. in our court before our  justices recovered against the same B. by an assise of mortdancestor taken between  the said D. and the same B., in which the same B. vouched the said A. to warranty  against the same D., who came and warranted it to him as land which his father had  given to the same B. But he was not bound to give escambium, as he says, because the  said D.'s paternal aunt C., on whose death the said D. brought the assise, was enfeoffed  of the said land by the said B.'s predecessors after the said A.'s father had given the  same land to the said B., as the same A. says.2 And have there etc. Witness etc. Hence  when it is proved that the same B. received such escambium, he will restore it as  wrongfully received. And that this is so may be found [in the roll] of Hilary term in the  fifteenth year of king Henry in the county of Berkshire, [the case] of the prior of  Bradley and William de Siffrewast.3
A warranty is sometimes suspended for a time because of minority or death.
 A warranty is sometimes temporarily suspended because of the warrantor's minority,4  sometimes because of his death,5 and sometimes because of a supervening fortuitous  circumstance.6 The principal action is not destroyed but continues, since its  foundation, that is, the principal plea, upon which an edifice may be constructed,  still continues, as where, while the principal parties,