Halakhah for Zevachim 200:19
לעולם דרבנן היא
Rabbi said: That is only as long as he was not buried; but if he was buried, [it is the day] without the [following] night. Now, this was reported before R'Jeremiah, whereupon he observed: That a great man like R'Joseph should say thus! Are we to assume then that Rabbi is more lenient? Surely it was taught: How long is he an onen on his account? As long as he is not buried, even for ten days: these are the words of Rabbi; but the Sages maintain: He observes aninuth on his account only on that day itself! Rather, explain it thus: How long does he observe aninuth on his account? The whole of that day without the [following] night. Rabbi maintained: As long as he is not buried, it embraces the [following] night.<span class="x" onmousemove="('comment',' This then is the controversy alluded to by R. Hisda.');"><sup>23</sup></span> Now, it was stated before Raba: Since Rabbi maintained that the day of burial embraces the [following] night by Rabbinical law,<span class="x" onmousemove="('comment',' Obviously by Rabbinical law only, for aninuth even on the day of burial itself is Rabbinical only.');"><sup>24</sup></span> it follows that the day of death embraces the [following] night by Scriptural law.<span class="x" onmousemove="('comment',' Just as aninuth on the day of death is Scriptural.');"><sup>25</sup></span> Does then Rabbi hold that aninuth at night is Scriptural? Surely it was taught: 'Behold, this day [etc].<span class="x" onmousemove="('comment',' Lev. X, 19. Aaron was explaining why he had not eaten of the sin-offering offered on the day of his consecration, viz., because he had lost two sons on that day.');"><sup>26</sup></span> I am forbidden by day yet am permitted at night;<span class="x" onmousemove="('comment',' Since there were no other priests to eat thereof.');"><sup>27</sup></span> but [future] generations will be forbidden both by day and by night':<span class="x" onmousemove="('comment',' Thus aninuth on the night following is Scriptural.');"><sup>28</sup></span> these are the words of R'Judah. Rabbi maintained: Aninuth at night is not Scriptural but a law of the Scribes! - In truth, it is Rabbinical.<span class="x" onmousemove="('comment',' Sc. the law of aninuth on the night after the day of death.');"><sup>29</sup></span>