Compare to Exodus 13:11 and following. The directions of the preceding legislation (see Numbers 18:15 and following) are here assumed, with the inj…

Only you shall not eat the blood thereof
Of the firstling:

you shall pour it upon the ground as w…

Here is instruction on what to do with the firstlings. We are not now limited as the Israelites were; we make no difference between a first calf, o…