Bg 9.24

aham hi sarva-yajnanam
bhokta ca prabhur eva ca
na tu mam abhijananti
tattvenatas cyavanti te

Word for word: 
aham — I; hi — surely; sarva — of all; yajnanam — sacrifices; bhokta — the enjoyer; ca — and; prabhuh — the Lord; eva — also; ca — and; na — not; tu — but; mam — Me; abhijananti — they know; tattvena — in reality; atah — therefore; cyavanti — fall down; te — they.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
I am the only enjoyer and master of all sacrifices. Therefore, those who do not recognize My true transcendental nature fall down.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Here it is clearly stated that there are many types of yajna performances recommended in the Vedic literatures, but actually all of them are meant for satisfying the Supreme Lord. Yajna means Visnu. In the Third Chapter of Bhagavad-gita it is clearly stated that one should only work for satisfying Yajna, or Visnu. The perfectional form of human civilization, known as varnasrama-dharma, is specifically meant for satisfying Visnu. Therefore, Krishna says in this verse, “I am the enjoyer of all sacrifices because I am the supreme master.” Less intelligent persons, however, without knowing this fact, worship demigods for temporary benefit. Therefore they fall down to material existence and do not achieve the desired goal of life. If, however, anyone has any material desire to be fulfilled, he had better pray for it to the Supreme Lord (although that is not pure devotion), and he will thus achieve the desired result.