TT #714 · Parashas Ki Seitzei · Seventh Aliyah · Passuk 25:07
And if the man does not desire to take his yevamah, then his yevamah shall go up to the gate to the elders and say: “My husband’s brother refuses to establish a name for his brother in Israel; he will not perform the duty of a husband’s brother for me.”
Torah Temimah points to Sifrei / Sanhedrin 17a.
TT lemma: אֶל הַזְּקֵנִים.
מְלַמֵּד שֶׁמִּצְוָה לְבֵית דִּין שֶׁיִּהְיוּ בִּזְקֵנִים.
English: This teaches that it is a mitzvah that the court consist of elders.
On the daf / in context: The ideal composition includes men of mature age.
Derash on the preferred composition of the court.
Preferably the chalitzah court is composed of elders.