SB 11.16.7

jñātvā jñāti-vadhaṁ garhyam
 adharmaṁ rājya-hetukam
tato nivṛtto hantāhaṁ
 hato ’yam iti laukikaḥ
Word for word: 
jñātvā — being aware; jñāti — of his relatives; vadham — the killing; garhyam — abominable; adharmam — irreligion; rājya — to acquire a kingdom; hetukam — having as the motive; tataḥ — from such activity; nivṛttaḥ — retired; haratā — the killer; aham — I am; hataḥ — killed; ayam — this group of relatives; iti — thus; laukikaḥ — mundane.
Translation: 
On the Battlefield of Kurukṣetra Arjuna thought that killing his relatives would be an abominable, irreligious activity, motivated only by his desire to acquire a kingdom. He therefore desisted from the battle, thinking, “I would be the killer of my relatives. They would be destroyed.” Thus Arjuna was afflicted with mundane consciousness.
Purport: 

Lord Kṛṣṇa here explains to Uddhava the circumstances in which Śrī Arjuna posed his questions.