Midrash for Menachot 163:3
אמר ר' אמי המתפיס מעות מעשר שני לשלמים לא קנו שלמים מאי טעמא דלא אלימא קדושת השלמים למיחל אקדושת מעשר שני
And in respect of peace-offerings [this is derived] from the expression 'there' stated [in connection with peace-offerings] and also in connection with the Second Tithe. Then it follows, as peace-offerings are not of the same kind as Second Tithe, so the [bread of the] thank-offering may not be from that which is the same kind as Second Tithe;<span class="x" onmousemove="('comment',' So that any Second Tithe wheat, even that which was bought with Second Tithe money, may not be used for the thank-offering. But he may buy with Second Tithe money wheat expressly for the thank-offering. V. p. 494. n. 5.');"><sup>5</sup></span> thus excluding wheat bought from Second Tithe money<span class="x" onmousemove="('comment',' For Second Tithe purposes but not for the thank-offering.');"><sup>6</sup></span>