Dora Bas Rivka Silver O'H
Twice a Day, Every Day (On Some Days, Even More!)
G-d told Moshe that when the Jews entered the land, they were to give the korban tamid, daily sacrifices, offered both morning and afternoon. Each tamid was to consist of a sheep with the appropriate flour offering and wine libation.
On Shabbos, there would be an additional offering of two sheep, with the appropriate flour and wine. This was on top of the two regular daily sacrifices.
There would also be an additional sacrifice every Rosh Chodesh. ("Rosh Chodesh" is typically translated "new moon," but that's not astronomically accurate as we use the term. It's the first day of a Hebrew month.) This sacrifice was to consist of two bulls, a ram and seven sheep, all with the appropriate amounts of flour and wine. A goat would also be offered on Rosh Chodesh, as a sin offering.
Our daily shacharis and mincha prayers, respectively recited in the morning and afternoon, correspond to the two daily tamid sacrifices. The musaf prayer recited on special occasions (such as Shabbos and Rosh Chodesh) corresponds to the additional sacrifices of the day.