Srimad-Bhagavatam: Canto 1 - Chapter 1 - Verse 5


तत्र ब्रह्मर्षय: सर्वे देवर्षयश्च सत्तम ।राजर्षयश्च तत्रासन् द्रष्टुं भरतपुङ्गवम् ॥ ५ ॥


tatra brahmarṣayaḥ sarvedevarṣayaś ca sattamarājarṣayaś ca tatrāsandraṣṭuṁ bharata-puṅgavam


Just to see the chief of the descendants of King Bharata [Bhīṣma], all the great souls in the universe, namely the ṛṣis amongst the demigods, brāhmaṇas and kings, all situated in the quality of goodness, were assembled there.


The ṛṣis are those who have attained perfection by spiritual achievements. Such spiritual achievements can be earned by all, whether one is a king or a mendicant. Bhīṣmadeva himself was also one of the brahmarṣis and the chief of the descendants of King Bharata. All ṛṣis are situated in the quality of goodness. All of them assembled there on hearing the news of the great warrior’s impending death.