SB 9.9.29

eṣa hi brāhmaṇo vidvāṁs
 tapaḥ-śīla-guṇānvitaḥ
ārirādhayiṣur brahma
 mahā-puruṣa-saṁjñitam
sarva-bhūtātma-bhāvena
 bhūteṣv antarhitaṁ guṇaiḥ
Synonyms: 
eṣaḥ — this; hi — indeed; brāhmaṇaḥ — a qualified brāhmaṇa; vidvān — learned in Vedic knowledge; tapaḥ — austerity; śīla — good behavior; guṇa-anvitaḥ — endowed with all good qualities; ārirādhayiṣuḥ — desiring to be engaged in worshiping; brahma — the Supreme Brahman; mahā-puruṣa — the Supreme Person, Kṛṣṇa; saṁjñitam — known as; sarva-bhūta — of all living entities; ātma-bhāvena — as the Supersoul; bhūteṣu — in every living entity; antarhitam — within the core of the heart; guṇaiḥ — by qualities.
Translation: 
Here is a learned, highly qualified brāhmaṇa, engaged in performing austerity and eagerly desiring to worship the Supreme Lord, the Supersoul who lives within the core of the heart in all living entities.
Purport: 

The wife of the brāhmaṇa did not regard her husband as a superficial brāhmaṇa who was called a brāhmaṇa merely because he was born of a brāhmaṇa family. Rather, this brāhmaṇa was actually qualified with the brahminical symptoms. Yasya yal lakṣaṇaṁ proktam (Bhāg. 7.11.35). The symptoms of a brāhmaṇa are stated in the śāstra:

śamo damas tapaḥ śaucaṁ
 kṣāntir ārjavam eva ca
jñānaṁ vijñānam āstikyaṁ
 brahma-karma svabhāvajam

“Peacefulness, self-control, austerity, purity, tolerance, honesty, wisdom, knowledge, and religiousness — these are the qualities by which the brāhmaṇas work.” (Bg. 18.42) Not only must a brāhmaṇa be qualified, but he must also engage in actual brahminical activities. Simply to be qualified is not enough; one must engage in a brāhmaṇa’s duties. The duty of a brāhmaṇa is to know the paraṁ brahma, Kṛṣṇa (paraṁ brahma paraṁ dhāma pavitraṁ paramaṁ bhavān). Because this brāhmaṇa was actually qualified and was also engaged in brahminical activities (brahma-karma), killing him would be a greatly sinful act, and the brāhmaṇa’s wife requested that he not be killed.