SB 5.3.17

śrī-bhagavān uvāca
aho batāham ṛṣayo bhavadbhir avitatha-gīrbhir varam asulabham abhiyācito yad amuṣyātmajo mayā sadṛśo bhūyād iti mamāham evābhirūpaḥ kaivalyād athāpi brahma-vādo na mṛṣā bhavitum arhati mamaiva hi mukhaṁ yad dvija-deva-kulam.
Synonyms: 
śrī-bhagavān uvāca — the Supreme Personality of Godhead said; aho — alas; bata — certainly I am pleased; aham — I; ṛṣayaḥ — O great sages; bhavadbhiḥ — by you; avitatha-gīrbhiḥ — whose words are all true; varam — for a benediction; asulabham — very difficult to achieve; abhiyācitaḥ — have been requested; yat — that; amuṣya — of King Nābhi; ātma-jaḥ — a son; mayā sadṛśaḥ — like Me; bhūyāt — there may be; iti — thus; mama — My; aham — I; eva — only; abhirūpaḥ — equal; kaivalyāt — because of being without a second; athāpi — nevertheless; brahma-vādaḥ — the words spoken by exalted brāhmaṇas; na — not; mṛṣā — false; bhavitum — to become; arhati — ought; mama — My; eva — certainly; hi — because; mukham — mouth; yat — that; dvija-deva-kulam — the class of pure brāhmaṇas.
Translation: 
The Supreme Personality of Godhead replied: O great sages, I am certainly very pleased with your prayers. You are all truthful. You have prayed for the benediction of a son like Me for King Nābhi, but this is very difficult to obtain. Since I am the Supreme Person without a second and since no one is equal to Me, another personality like Me is not possible to find. In any case, because you are all qualified brāhmaṇas, your vibrations should not prove untrue. I consider the brāhmaṇas who are well qualified with brahminical qualities to be as good as My own mouth.
Purport: 

The word avitatha-gīrbhiḥ means “they whose spoken vibrations cannot be nullified.” The brāhmaṇas (dvija, the twice-born), are given a chance by the śāstric regulations to become almost as powerful as the Supreme Lord. Whatever a brāhmaṇa speaks cannot be nullified or changed in any circumstance. According to the Vedic injunctions, a brāhmaṇa is the mouth of the Supreme Personality of Godhead; therefore in all rituals a brāhmaṇa is offered food (brāhmaṇa-bhojana) because when a brāhmaṇa eats, it is considered that the Supreme Lord Himself eats. Similarly, whatever a brāhmaṇa speaks cannot be changed. It must act. The learned sages who were priests at Mahārāja Nābhi’s sacrifice were not only brāhmaṇas but were so qualified that they were like devas, demigods, or God Himself. If this were not the case, how could they invite Lord Viṣṇu to come to the sacrificial arena? God is one, and God does not belong to this or that religion. In Kali-yuga, different religious sects consider their God to be different from the God of others, but that is not possible. God is one, and He is appreciated according to different angles of vision. In this verse the word kaivalyāt means that God has no competitor. There is only one God. In the Śvetāśvatara Upaniṣad (6.8) it is said, na tat-samaś cābhyadhikaś ca dṛśyate: “No one is found to be equal to Him or greater than Him.” That is the definition of God.