Moses's answer to Pharaoh's last offer is one of the most famous lines in Exodus.
"Our flocks, moreover, must go with us; not one hoof of them shall remain; for from them we are to take, to do service before the Lord our God. We cannot leave them; for we know not (as yet) in what manner we are to worship before the Lord, until we come thither" (Targum Pseudo-Jonathan on Exodus 10:26).
The Aramaic paraphrase, preserved in the Targum attributed to Yonatan ben Uzziel, records the phrase that would echo through Jewish history — lo tish'ar tilf'ta, not one hoof will be left. Not a single head of livestock. Not a lamb. Not a calf.
Moses gives a reason that Pharaoh cannot refute. The sacrifices themselves have not yet been prescribed. Israel does not know which animals the Holy One will require. A bull? A ram? A goat? A turtledove? Without revelation at Sinai, the people cannot pre-select which flocks to take and which to leave. So they must take them all.
This is a stunningly humble theological posture. Moses is essentially saying: we are going out into the wilderness not yet knowing how to worship. We will learn the service at the mountain. Until then, we bring everything, because the Holy One has not yet told us what He wants.
The Maggid teaches: the journey of Torah begins with not-knowing. Israel left Egypt with their flocks but without their liturgy, their laws, their calendar of feasts. They walked into the desert to receive what they could not carry out. The Exodus is the story of a people willing to leave slavery before they knew what freedom would require of them.