later kings.
The offering of the firstborn is only "the expression of thankfulness to
the Deity for fruitful flocks and herds. If claim is also laid to the
human firstborn, this is merely a later generalisation" (Wellhausen, p.
88).[21]

But this claim is by no means the only stumbling-block in the way of the
theory, serious a stumbling-block though it be. How came the bright
festival to be spoiled by bitter herbs and "bread of affliction"? Is it
natural that a merry feast should grow more austere as time elapses? Do
we not find it hard enough to prevent the most sacred festivals from
reversing the supposed process, and degenerating into revels? And is not
this the universal experience, from San Francisco to Bombay? Why was the
mandate given to sprinkle the door of every house with blood, if the
story originated after the feast had been centralised in Jerusalem,
when, in fact, this precept had to be set aside as impracticable, their
homes being at a distance? Why, again, were they bidden to slaughter the
lamb "between the two evenings" (Exod. xii. 6)--that is to say, between
sunset and the fading out of the light--unless the story was written
long before such numbers had to be dealt with that the priests began to
slaughter early in the afternoon, and continued until night? Why did the
narrative set forth that every man might slaughter for his own house (a
custom which still existed in the time of Hezekiah, when the Levites
only slaughtered "the passovers" for those who were not ceremonially
clean, 2 Chron. xxx. 17), if there were no stout and strong historical
foundation for the older method?

Stranger still, why was the original command invented, that the lamb
should be chosen and separated four days before the feast? There is no
trace of any intention that this precept should apply to the first
passover alone. It is somewhat unexpected there, interrupting the hurry
and movement of the narrative with an interval of quiet expectation, not
otherwise hinted at, which we comprehend and value when discovered,
rather than anticipate in advance. It is the very last circumstance
which the Priestly Code would have invented, when the time which could
be conveniently spent upon a pilgrimage was too brief to suffer the
custom to be perpetuated. The selection of the lamb upon the tenth day,
the slaying of it at home, the striking of the blood upon the door, and
the use of hyssop, as in other sacrifices, with which to sprinkle it,