(Devarim 16:15) "Seven days shall you celebrate before the L-rd your G-d": I might think that he sacrifices the festive offering (chagigah) all seven days; it is, therefore, written (Vayikra 43:41) "And you shall celebrate it" (the first day), and not all seven days.

If so, how is "seven days" to be understood? As referring to compensation (i.e., if he did not offer the chagigah on the first day, he can do so all seven days.

"For the L-rd your G-d will bless you": I might think, only in that species (which he sacrifices); it is, therefore, written "in all of your produce and in all to which you put your hand."

"and you shall be only happy": to include the night of the last day of the festival for rejoicing.

I might think also to include the night of the first day of the festival; it is, therefore, written "only" (to exclude this).

From here it was taught: One may fulfill his obligation [of rejoicing] with meat of voluntary sacrifices. I might have thought [that one can likewise fulfill his obligation] with fowl and meal-offerings? Therefore it states "Only..." [to exclude this].