The following verse is one of the paragraphs of the Shema, said twice per day in Jewish liturgy:
Deuteronomy 11:13-15 13 And it shall come to pass, if ye shall hearken diligently unto my commandments which I command you this day, to love the LORD your God, and to serve him with all your heart and with all your soul, 14 That I will give you the rain of your land in his due season, the first rain and the latter rain, that thou mayest gather in thy corn, and thy wine, and thine oil. 15 And I will send grass in thy fields for thy cattle, that thou mayest eat and be full.
The Midrash “Sifre Deut., 80a, Section 41) defines “service of the heart”: “And to serve him (Deut 11:13): This refers to prayer. You might say, “This refers to prayer (according to you), but might it not refer to (Temple) service?” (The answer is no.) Since Scripture says, “With all your heart and all your soul (Duet 11:13), is there such thing a (Temple) Service in one’s heart? Therefore, what does the verse mean by “and to serve him”? It refers to prayer.”
Thus, the word “AVODAH” is the usual word for liturgy in Rabbinical liturgy. “AVODAH” refers to the service of the priests, in offering sacrifices.