"And entering therewith into the midst of a multitude"—meaning: a multitude of people upon whom they made a raid; that is, the enemy.
Muhammad said: The meaning of "wasatna" (they entered into the midst) is that they penetrated into the middle.
Yahya said: All of this is an oath.
﴿فوسطن بِهِ جمعا﴾ أَيْ: جَمْعًا مِنَ النَّاسِ أَغَارَتْ عَلَيْهِ؛ يَعْنِي: مِنَ الْعَدُوِّ.
قَالَ مُحَمَّد: معنى (وسطن): تَوَسَّطْنَ.
قَالَ يَحْيَى: وَهَذَا كُلُّهُ قسم