Reference for Menachot 181:19
אבל היכא דקא מייתי שתי עולות חדא בנדר וחדא בנדבה אי נמי שני שלמים אחד בנדר ואחד בנדבה אימא שם שלמים אחת היא שם עולה אחת היא ותיסגי ליה בנסכים דחד קמ"ל
- It was necessary, for [without it] I might have thought that that<span class="x" onmousemove="('comment',' That for each offering drink-offerings are required.');"><sup>23</sup></span> was so only where one brought a burnt-offering and a peace-offering both in fulfilment of a vow or both as freewill-offerings, but where one brought two burnt-offerings one in fulfilment of a vow and one as a freewill-offering, or two peace-offerings one in fulfilment of a vow and one as a freewill-offering, since there is only one type of offering here, viz. , the peace-offering or the burnt-offering, it is sufficient if the drink-offerings for one only are brought; we are therefore taught [otherwise].