220 COMMON ANCIENT DOCTRINE

The plots adjoined or opened on the same lane. Final systematic consistency was achieved in Iraq only in the time of Abū Ḥanīfa and his companions who gave the right to pre-emption to the owner of a share in undivided property in the first place,¹ then to the owner of a separate plot who had, however, retained a common interest in the lane, and finally to the owner of an adjoining plot.²

Besides and beyond cross-references, there exist cross-influences, cases where the doctrine of one particular school was taken over by another in the pre-literary period. In contrast to the mutual character of the formal reactions of the Iraqians and the Medinese to one another's doctrines, we notice that the material influences almost invariably start from the Iraqians and not from the Medinese. We found that Iraqian legal maxims were taken over by the Medinese, but not vice versa;³ and we saw that an early Iraqian qiyās spread into Hijaz and there produced traditions from the Prophet.⁴

A further example is provided by the doctrine of 'umrā and suknā, a kind of temporary gift.⁵ Etymology and old Arabic usage show that 'umrā was originally a temporary gift, to revert to the donor at the death of the donee;⁶ suknā meant the same with regard to a dwelling house. This was indeed the doctrine of the Medinese on 'umrā and suknā. The ancient Iraqians, however, considered 'umrā, but not suknā, as an unconditional gift which did not return to the donor but became the full property of the donee. This doctrine is expressed in a tradition, which claims to be transmitted by Jābir from the Prophet and which exists in two versions, one with an Iraqian and the other with a Medinese isnād. The main transmitter in this last isnād is the ancient Medinese authority, Sulaimān b. Yasār. The Iraqian version reflects the change from the original concept of 'umrā to the Iraqian doctrine which is secondary; the Medinese version, in an additional remark, gives the kind of rudimentary technical reasoning which caused the change of doctrine; this explanatory remark soon became fused with the main body of