Bg 10.33

akṣarāṇām a-kāro ’smi
dvandvaḥ sāmāsikasya ca
aham evākṣayaḥ kālo
dhātāhaṁ viśvato-mukhaḥ
Synonyms: 
akṣarāṇām — of letters; a-kāraḥ — the first letter; asmi — I am; dvandvaḥ — the dual; sāmāsikasya — of compounds; ca — and; aham — I am; eva — certainly; akṣayaḥ — eternal; kālaḥ — time; dhātā — the creator; aham — I am; viśvataḥ-mukhaḥ — Brahmā.
Translation: 
Of letters I am the letter A, and among compound words I am the dual compound. I am also inexhaustible time, and of creators I am Brahmā.
Purport: 

A-kāra, the first letter of the Sanskrit alphabet, is the beginning of the Vedic literature. Without a-kāra, nothing can be sounded; therefore it is the beginning of sound. In Sanskrit there are also many compound words, of which the dual word, like rāma-kṛṣṇa, is called dvandva. In this compound, the words rāma and kṛṣṇa have the same form, and therefore the compound is called dual.

Among all kinds of killers, time is the ultimate because time kills everything. Time is the representative of Kṛṣṇa because in due course of time there will be a great fire and everything will be annihilated.

Among the living entities who are creators, Brahmā, who has four heads, is the chief. Therefore he is a representative of the Supreme Lord, Kṛṣṇa.