וַיִּקַּ֤ח שְׁמוּאֵל֙ אֶת־שָׁא֣וּל וְאֶֽת־נַעֲר֔וֹ וַיְבִיאֵ֖ם לִשְׁכָּ֑תָה וַיִּתֵּ֨ן לָהֶ֤ם מָקוֹם֙ בְּרֹ֣אשׁ הַקְּרוּאִ֔ים וְהֵ֖מָּה כִּשְׁלֹשִׁ֥ים אִֽישׁ׃
And Samuel took Saul and his servant, and brought them into the chamber, and made them sit in the chiefest place among them that were bidden, who were about thirty persons.
Gur Aryeh
Ten male donkeys. See Rashi. The donkeys were a hint that in selling him the ten brothers were like mere beasts of burden, fulfilling someone else’s purposes uncomprehendingly. That is, Hashem had used them to bring about this salvation.