ابن سهل
The courtyard of the mosque was planted with trees from at least as early as 808, according to the jurist Ibn Sahl, who himself cited five previous authorities. Although the species of tree is not known, the fact that these were fruit trees is attested in Ibn Sahl, who was consulted as to whether such a garden was forbidden and, if not forbidden, whether it was permitted to eat from it. That the trees remained in the courtyard is demonstrated by two seals of the City of Cordoba, one in 1262 and the other in 1445, both of which show the mosque (which by then had been converted to a cathedral) within whose walls appear tall palm trees. With secure evidence of its early date, this courtyard is the oldest continuously planted Islamic garden in the world.