- " What happened there was that prior to beginning the prayer service, they did a final count to make sure all ten people were in the room.
I imagine he was counting to ten by using Psalms 28:9, which is comprised of exactly ten words.1 Typically, one person recites the verse word by word while pointing at each person in the quorum. When he reaches the last word, everyone knows that there are ten people in the room, and prayers can begin.
This stems from an ancient tradition not to count Jews with numbers.
When the Jews escaped from Egypt and began their journey through the desert to the Land of Israel, G‑d requested that a census be carried out. However the actual counting of the Jews was not done in the conventional way. G‑d commanded each person to give a half of the ancient shekel coin in a nationwide collection, following which Moses would count the coins and know how many Jews there were.
In Exodus 30:11–13 we read: “And G‑d spoke to Moses, saying: When you take the sum of the children of Israel according to their numbers, let each one give to G‑d an atonement for his soul when they are counted, then there will be no plague among them when they are counted. This they shall give, everyone who passes through the counting, half a shekel [coin] . . .”"