In this age, however, one must take into account that the brahmanas are uncertain in their qualifications. Because there are no yajnic brahmanas, all yajnas are forbidden

Expressions researched:
"In this age, however, one must take into account that the brāhmaṇas are uncertain in their qualifications. Because there are no yajñic brāhmaṇas, all yajñas are forbidden"

Srimad-Bhagavatam

SB Canto 10.1 to 10.13

Brāhmaṇas fully equipped with the brahminical qualifications are always yogīs fully powerful in mystic yoga. Their words never fail. In every transaction with other members of society, brāhmaṇas are certainly dependable. In this age, however, one must take into account that the brāhmaṇas are uncertain in their qualifications. Because there are no yajñic brāhmaṇas, all yajñas are forbidden.

SB 10.7.17, Translation and Purport

The brāhmaṇas, who were completely expert in chanting the Vedic hymns, were all yogīs fully equipped with mystic powers. Whatever blessings they spoke were certainly never fruitless.

Brāhmaṇas fully equipped with the brahminical qualifications are always yogīs fully powerful in mystic yoga. Their words never fail. In every transaction with other members of society, brāhmaṇas are certainly dependable. In this age, however, one must take into account that the brāhmaṇas are uncertain in their qualifications. Because there are no yajñic brāhmaṇas, all yajñas are forbidden. The only yajña recommended in this age is saṅkīrtana-yajña. Yajñaiḥ saṅkīrtana-prāyair yajanti hi sumedhasaḥ (SB 11.5.32). Yajña is meant to satisfy Viṣṇu (yajñārthāt karmaṇo 'nyatra loko 'yaṁ karma-bandhanaḥ (BG 3.9))). Because in this age there are no qualified brāhmaṇas, people should perform yajña by chanting the Hare Kṛṣṇa mantra (yajñaiḥ saṅkīrtana-prāyair yajanti hi sumedhasaḥ). Life is meant for yajña, and yajña is performed by the chanting of Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare.