Bhīṣma is one of the authorities, authorities of religious principle. There are twelve authorities.
- svayambhūr nāradaḥ śambhuḥ
- kumāraḥ kapilo manuḥ
- prahlādo janako bhīṣmo
- balir vaiyāsakir vayam
- (SB 6.3.20)
There are four, twelve authorities. One of them is Bhīṣma. Prahlādo janako bhīṣmo balir vaiyāsakir vayam. So Bhīṣma is not ordinary person. Therefore he said, katham, gurūn ahatvā hi mahānubhāvān śreyo bhoktuṁ bhaikṣyam apīha loke (BG 2.5). "I do not like to kill my guru, who is so great, and my grandfather. Better I shall become a beggar." A kṣatriya's business is not to beg. A brāhmaṇa can beg.