Our tasbihs are wonderful objects. I usually carry at least one with me at all times. Of course, somewhere on the back corner of our parents' refrigerator, there's a magnet with Hazar Imam's photo and a short farman about using a tasbih all the time. But my favourite reasons to use a tasbih comes from a story from a Sufi sheikh in Yugoslavia:
Once upon a time, the princess was sick. All the doctors in the court agreed there's nothing that could be done for her. So, the sultan called for Pir Nureddin Jerrahi, because he could heal people. The Pir suggested calling the name of Allah over her and the doctors all laughed at him. So the Pir replied: "you idiots don't know nothing." The doctors got pissed and were about to wreck the Pir's whole face up, but then he said: "why is it that when I call you 'idiots', you get mad, but you don't think calling 'Allah' can make you feel better?"
beads on string
Beaded counting devices far precede tasbihs, or even Islam. Some of the earliest beads found, dated to over a hundred thousand years ago. Because of beads' limited use, and because these were found at a burial site, it's entirely possible that these shell beads could have been prayer prayer implements.
The earliest recorded use of prayer beads comes from Hinduism in the form of a statue from the third century, BCE of a man using beads for prayer. Since then, beads have been used to call prayers in Hinduism, Buddhism, and Sikhism (माला "mala" in Sanskrit), Christianity (Prayer Ropes and Rosaries), and in different sects of Islam (مسبحة "misbaha" in Arabic and تسبيح "tasbih" also in Arabic).
In Hinduism and Buddhism, the material that the beads are made from also has a significance to the prayer: seeds represent rebirth, crystals lend clarity, the most powerful Buddhist garlands are made from human bones.
number of beads
According to Twelver scholar Muhammad Baqir Majlisi, Fatima made the first Muslim prayer beads out of soil from the graves of those killed in the Battle of Uhud. She would use this to recite "Fatima's Prayer" which is still practiced today ("Praise to God", "God is perfect", and "God is great" 33 times each). But not much is known about where the number 33 came from.
For three hundred years before Muhammad, Christian monks in Alexandria prayed on ropes with 33 knots or 33 beads. That significance comes from the 33 years Jesus lived on Earth. These 33-beaded prayer implements were around in Mecca during the time of the Prophet, so it's possible he was influenced by the Christian practice when creating Fatima's prayer.
There are also Muslim prayer beads that come with 99 beads. These are said to represent the 99 names of God.
Growing up, I was always instructed to count on a tasbih with my right hand, and "treat it with respect". This notion probably comes from the strict restrictions surrounding Hindu prayer beads. When praying on a mala, you should always use your right hand, because your left hand is considered dirty. Each bead is moved with either the thumb or the ring finger, being careful not to touch the mala with your pointer finger, which represents ego.
In my own experience, it's Ismailis that come from South Asian heritage that insist on using only the right hand. I've seen older Jamati members from Central Asia using their left hand when the right is preoccupied. These same Jamati members also often use both hands when offering blessings. And because there's no hand-preference in Islam (aside from one hadith about eating food), I'm assuming the preference for right-handedness comes from South Asian culture, and not anything religious.
wearing a tasbih
Nowadays, wrist-tasbihs are in style. Aside from their fashion component, they're supposed to be a constant reminder to use the tasbih throughout the day. Sufis also use their clothes as a constant reminder to pray: they wear rough, woolen robes that are stiff and itchy. That reminds them to pray in order to gain spiritual comfort to ease their physical discomfort. The Christian monks from Alexandria wore their prayer ropes around their left wrist. This was to remind themselves to pray, but on the left arm so that they're not showing off their religiosity to other people. I'm not sure the same can be said for the incredibly sparkly wrist tasbihs we have today.
Many people have raised objections to wrist-tasbihs, saying that they can easily become dirty. Again, this comes from the South Asian tradition. Following Ismaili esotericism, the tasbih's cleanliness wouldn't have an effect on its spiritual effectiveness.
In Hinduism the prayer beads should be put away when not in use. Monks and other holy figures often wear their prayer beads around their neck to show that they're in a constant state of prayer. In Sikhism, although they're not popular, prayer beads are often worn around the neck as a reminder to pray. I haven't seen any Ismailis wear a tasbih around their neck, but I'm not sure if that's traditional, or just because most tasbihs have 33 beads and are too small to fit around someone's neck.
Outside of any religious significance, tasbihs can also serve a practical purpose. In Greece, worry beads (κομπολόι "kombolói" in Greek) and begleri (μπεγλέρι in Greek) are often used just to keep people's hands occupied. You can buy them in all the tourist spots, and can often see people doing tricks by flipping them around their fingers. They're a lot like fidget spinners. Like fidget spinners, these worry beads are used to ease anxiety, and help people stay focused, by giving their hands something to do.
Tasbihs can serve a similar purpose. I often find myself fingering my tasbih, or flipping it over my fingers, or spinning it around my hand, even when I'm not praying.
Would you like to by a durable, quiet rope tasbih to commemorate the Diamond Jubilee?