TT #678 · Parashas Ki Seitzei · Seventh Aliyah · Passuk 25:05
When brothers dwell together and one of them dies and has no son, the wife of the dead shall not be outside to a strange man; her husband’s brother shall come upon her and take her to himself as a wife and perform the duty of a husband’s brother for her.
Torah Temimah points to Yevamot 39a / Kiddushin 14b.
TT lemma: וּלְקָחָהּ לוֹ לְאִשָּׁה.
יְבָמָהּ יָבֹא עָלֶיהָ – זוֹ בִּיאָה; וּלְקָחָהּ לוֹ לְאִשָּׁה – זֶה הַמַּאֲמָר. יָכוֹל כְּשֵׁם שֶׁהַבִּיאָה גּוֹמֶרֶת בָּהּ כָּךְ הַמַּאֲמָר גּוֹמֵר בָּהּ? תַּלְמוּד לוֹמַר וְיִבְּמָהּ.
English: “Her yavam shall come upon her” — this is bi’ah; “and he shall take her to himself as a wife” — this is ma’amar. Might one think that just as bi’ah completes the acquisition, so ma’amar completes it? Scripture says “and he shall perform the duty of a husband’s brother.”
On the daf / in context: Ma’amar creates only a partial bond; only bi’ah finishes the acquisition of the yevamah.
Derash distinguishing ma’amar from bi’ah.
Ma’amar does not complete yibbum; its effect is to forbid the woman to the other brothers until bi’ah or chalitzah occurs.