In 1610 George Sandys noted that the floor of St. Sophia was furnished with "rewes of mats". Mosque floor coverings are regularly noted by other travellers, with mats conspicuous among them in the 17th century, thus:
An excruciatingly detailed, interminable description of the St. Sophia mosque, by Grelot c. 1680, contains a listing of minor mosque functionaries. This includes "... the Klimgiler or Carpeteers, to whom is entrusted the care of carpets. The Kaimgilier...who must clean them often..." (5) The existence of such a position would be consistent with a carpet status of regular mosque furnishing.
These observations of matters Ottoman and Turkic suggest that 17th century floor coverings were a mixture of mat and carpet, with mats declining and carpets predominating toward the end of the century. If so, then the 17th century becomes a transitional period, and carpeting becomes, perhaps, a practice of the modern era. The time at which carpets came into general use as floor covering is of interest, obviously, as such period necessarily constitutes the earliest date which can be assigned to rugs found in mosques on the basis of their being there. Earlier dating would require other evidence.
The individual prayer carpet is noted in Ottoman Turkey by Thevenot (c.l660) (6) Rycault, however, (1664, "handkerchief" ) (7) and Sandys (1610, "upper garments") (8) when identifying things prayed upon did not mention rugs, but indicated other objects. From the travel accounts, there may be some question whether the prayer carpet was in general use at this time in Ottoman Turkey.
These matters of prayer rugs and of mosque mats and carpets need to be taken into account by any speculation involving saffs. Saffs are nowhere mentioned by 17th century travellers. Thevenot, a sharp-eyed observer, knew the prayer carpet and referred to mosque floor covering merely as "carpets". While a datum is not a statistic, his notations and the tenor of other accounts are cautionary about whether saffs were in use at this time, in Ottoman mosques and elsewhere.