Translation:Mishnah/Seder Moed/Tractate Taanit/Chapter 4/1

On three occasions during the year the priests raise up their hands [to bless the people three times during the day, during the shemonah esreh prayer. And on Yom Kippur they would raise their hands] four times during the day; at shahrit, mussaf, minhah, and ne'ilah. [These three occasions are]: on fast days, on ma'amadot, and on Yom Kippur. [Taanis, 4:1]