Tzav, Tsav, Zav, Sav, or Ṣaw (צַו — Hebrew for "command," the sixth word, and the first distinctive word, in the parashah) is the 25th weekly Torah portion (פָּרָשָׁה, parashah) in the annual Jewish cycle of Torah reading and the second in the Book of Leviticus. The parashah teaches how the priests performed the sacrifices and describes the ordination of Aaron and his sons
(summary from Wikipedia.org)