Part of the reason I have this impression is undoubtedly because I don't read or speak the relevant languages of the main Islamic cultural areas, most notably Arabic. I can testify that, at least, very little has been published in English about Islamic rosaries. I am also not myself a Muslim, so there are undoubtedly sources of information that I wouldn't know about. But I've asked a few Islamic scholars for help, and they have also come up blank. If anyone out there has solid information on Islamic rosaries before about 1600 AD, or 1000 AH in the Islamic dating system, I'd love to know about it.
One of the persistent myths about the European Middle Ages is the idea that the Christian Crusaders brought back new customs and ideas from their contact with Islam. In many cases this is demonstrably not true, because there is already evidence in Europe of those ideas before the Crusades. That seems to be the case with the concept of prayer beads as well. There are not a lot of earlier records of Christians using prayer beads, but there are a few.
In fact, there has been some speculation that Muslims got the idea of counting prayers on a string of beads from Christian sources -- specifically from the Eastern Christian traditions, which tend to use strings of 99 or 100 beads. The Muslim tasbih or rosary is generally either 99 or 33 beads long, as opposed to the usual European preference for groups of 10 or 50.
As far as I know, prayer beads are not mentioned in the Koran. But the idea may very well have been known to the Prophet's early followers. Collections of sayings attributed to the Prophet, known as hadith, are a major source of information about Islamic custom, thought and culture, and translations of these are appearing on the Internet, so I went looking to see what I could find.
From this translation of the Partial Sunan Abu Dawud, I found:
Book 8, Number 1495:
Narrated Sa'd ibn AbuWaqqas:
Once Sa'd, with the Apostle of Allah (peace_be_upon_him), visited a woman in front of whom were some date-stones or pebbles which she was using as a rosary to glorify Allah. He (the Prophet) said: I tell you something which would be easier (or more excellent) for you than that. He said (it consisted of saying): "Glory be to Allah" as many times as the number of that which He has created in Heaven; "Glory be to Allah" as many times as the number of that which He has created on Earth; "Glory be to Allah" as many times as the number of that which He has created between them; "Glory be to Allah" as many times as the number of that which He is creating; "Allah is most great" a similar number of times; "Praise (be to Allah)" a similar number of times; and "There is no god but Allah" a similar number of times; "There is no might and no power except in Allah" a similar number of times.
Book 8, Number 1496:
Narrated Yusayrah, mother of Yasir:
The Prophet (peace_be_upon_him) commanded them (the women emigrants) to be regular (in remembering Allah by saying): "Allah is most great"; "Glory be to the King, the Holy"; "there is no god but Allah"; and that they should count them on fingers, for they (the fingers) will be questioned and asked to speak.
Book 8, Number 1497:
Narrated Abdullah ibn Amr ibn al-'As:
I saw the Apostle of Allah (peace_be_upon_him) counting the glorification of Allah on fingers.
This passage seems to be the main source for the belief that counted prayers go back to the time of the Prophet Mohammed himself. But you'll note that the first part of it does not, in fact, involve counting, since the numbers recommended are quantities like "as many times as the number of that which He has created in Heaven" which is infinite or nearly so. (Compare the Christian "Pray without ceasing.")
The number 33 seems to come from another passage in the same collection:
Book 8, Number 1499:
AbuDharr said: Prophet of Allah. The wealthy people have all the rewards; they pray as we pray; they fast as we fast; and they have surplus wealth which they give in charity; but we have no wealth which we may give in charity.
The Apostle of Allah (peace_be_upon_him) said: AbuDharr, should I not teach you phrases by which you acquire the rank of those who excel you? No one can acquire your rank except one who acts like you.
He said: Why not, Apostle of Allah? He said: Exalt Allah (say: Allah is Most Great) after each prayer thirty-three times; and praise Him (say: Praise be to Allah) thirty-three times; and glorify Him (say: Glory be to Allah) thirty-three times, and end it by saying, "There is no god but Allah alone, there is no partner, to Him belongs the Kingdom, to Him praise is due and He has power over everything". His sins will be forgiven, even if they are like the foam of the sea.
(to be continued)