Sanskrit
श्वशुरान्सुहृदश्चैव सेनयोरुभयोरपि । तान्समीक्ष्य स कौन्तेयः सर्वान्बन्धूनवस्थितान् ॥
śvaśurān suhṛdaś caiva senayor ubhayor api tān samīkṣya sa kaunteyaḥ sarvān bandhūn avasthitān
Translation
Fathers-in-law and benefactors also in both armies; seeing all these kinsmen thus standing arrayed, Kaunteya,
Annie Besant · The Bhagavad-Gita, translated by Annie Besant (4th ed., 1922) — Wikisource · Public Domain
Explanation
The crucial detail closing out verse 26’s list: these relationships exist “in both armies” — this isn’t Arjuna’s family on one side and strangers on the other, it’s one extended family standing on opposite sides of the same field. That fact is what verse 28’s reaction responds to.