Its invention is attributed to St. Pachomius in the fourth
century as an aid for illiterate monks to accomplish a
consistent number of prayers and prostrations. Monks were often
expected to carry a prayer rope with them, to remind them to
pray constantly in accordance with St. Paul's injunction in I
Thessalonians 5:17, "Pray without ceasing." In some Russian
Orthodox service books, certain services can be replaced at need
by praying the Jesus Prayer a specified number of times,
anywhere from 300 to 1,500 times depending on the service being
replaced. In this way prayers can still be said even if the
service books are unavailable for some reason. The use of a
prayer rope is a very practical tool in such cases, simply for
keeping count of the prayers said. Another form of prayer rope
was formerly in use in Russia, and is still preserved among the
Old Believers. It is called lestovka ("ladder"), and is arranged
asymmetrically. Whereas the more common 100-knot prayer rope is
divided into four sets of 25 knots eac