Reference for Kiddushin 2:1
הָאִישׁ מְקַדֵּשׁ בּוֹ וּבִשְׁלוּחוֹ. הָאִשָּׁה מִתְקַדֶּשֶׁת בָּהּ וּבִשְׁלוּחָהּ. הָאִישׁ מְקַדֵּשׁ אֶת בִּתּוֹ כְּשֶׁהִיא נַעֲרָה, בּוֹ וּבִשְׁלוּחוֹ. הָאוֹמֵר לְאִשָּׁה, הִתְקַדְּשִׁי לִי בִתְמָרָה זוֹ, הִתְקַדְּשִׁי לִי בְזוֹ, אִם יֵשׁ בְּאַחַת מֵהֶן שָׁוֶה פְרוּטָה, מְקֻדֶּשֶׁת. וְאִם לָאו, אֵינָהּ מְקֻדֶּשֶׁת. בְּזוֹ וּבְזוֹ וּבְזוֹ, אִם יֵשׁ שָׁוֶה פְרוּטָה בְּכֻלָּן, מְקֻדֶּשֶׁת. וְאִם לָאו, אֵינָהּ מְקֻדֶּשֶׁת. הָיְתָה אוֹכֶלֶת רִאשׁוֹנָה רִאשׁוֹנָה, אֵינָהּ מְקֻדֶּשֶׁת, עַד שֶׁיְּהֵא בְאַחַת מֵהֶן שָׁוֶה פְרוּטָה:
A man betroths by himself and by his messenger. [First, by himself; then, by his messenger, his own doing it being preferred to his messenger's. For when he himself performs the mitzvah his reward is greater. We derive that a man's messenger is like himself from (Exodus 12:6): "And the entire assembly of the congregation of Israel shall slaughter it." Now do all of Israel slaughter it? From here it is derived that one's messenger is like himself.] A man betroths his daughter when she is a maiden (na'arah) [and, it goes without saying, when she is a minor (k'tanah). "Na'arah" is stated to teach proper conduct: that one is forbidden to betroth his daughter when she is a minor, until she is grown enough to say: "I desire (to wed) that man."] If one says to a woman: "Be betrothed to me for this date; be betrothed to me for this" — if one of them is worth a p'rutah, she is betrothed; if not, she is not betrothed. [For since he said: "Be betrothed; be betrothed," each (date) is (designated) for betrothal in itself. (If he said: "Be betrothed to me) for this and for this and for this" — if there is the worth of a p'rutah among all, she is betrothed; if not, she is not betrothed. ] If she ate them one by one, she is not betrothed, unless one of them were worth a p'rutah. [This "one of them" must be the last one. For if he said: "Be betrothed to me for this and for this and for this," and she ate them one by one, each one that she ate is a loan to her, and when she comes to the last, whereby the betrothal is consummated, if it is worth a p'rutah, she is betrothed with a loan and a p'rutah. And the ruling is that if one betroths with a loan and a p'rutah, the woman is intent upon the p'rutah, and she is betrothed. But if the last were not worth a p'rutah, even though the first were worth a p'rutah, at the consummation of the betrothal he betroths with a loan, and if one betroths with a loan, she is not betrothed.]