Bg 10.33

aksaranam a-karo ’smi
dvandvah samasikasya ca
aham evaksayah kalo
dhataham visvato-mukhah

Word for word: 
aksaranam — of letters; a-karah — the first letter; asmi — I am; dvandvah — the dual; samasikasya — of compounds; ca — and; aham — I am; eva — certainly; aksayah — eternal; kalah — time; dhata — the creator; aham — I am; visvatah-mukhah — Brahma.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
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 Brahma.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
A-kara, the first letter of the Sanskrit alphabet, is the beginning of the Vedic literature. Without a-kara, 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 rama-Krishna, is called dvandva. In this compound, the words rama and Krishna 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 Krishna because in due course of time there will be a great fire and everything will be annihilated.

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