Reference for Eruvin 54:13
במאי קא מיפלגי רבי יהודה בן גדיש ור"א והני תנאי דלקמן ר' יהודה בן גדיש ור"א דרשי רבויי ומיעוטי והני תנאי דרשי כללי ופרטי
[to indicate] that [it may be bought] even together with its wool. What however, was the need for the expression of<span class="x" onmousemove="('comment',' Lit., 'wherefore to me'.');"><sup>30</sup></span> 'for oxen'?<span class="x" onmousemove="('comment',' In Deut. XIV, 26.');"><sup>26</sup></span> And should you reply that if the All Merciful had not written 'for oxen' it might have been assumed that a sheep may be bought together with its skin but not together with its wool [and that] the All Merciful has therefore written 'for oxen' to include its skin so that 'sheep' remained superfluous in order to include its wool [it could be retorted that even] if the All Merciful had not written 'oxen' no one would have suggested that a sheep may be bought only<span class="x" onmousemove="('comment',' Lit., 'yes'.');"><sup>31</sup></span>