SB 9.4.22
ije ’svamedhair adhiyajñam isvaram
maha-vibhutyopacitanga-daksinaih
tatair vasisthasita-gautamadibhir
dhanvany abhisrotam asau sarasvatim
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In desert countries where there flowed the river Sarasvati, Maharaja Ambarisa performed great sacrifices like the asvamedha-yajña and thus satisfied the master of all yajñas, the Supreme Personality of Godhead. Such sacrifices were performed with great opulence and suitable paraphernalia and with contributions of daksina to the brahmanas, who were supervised by great personalities like Vasistha, Asita and Gautama, representing the king, the performer of the sacrifices.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When one performs ritualistic sacrifices as prescribed in the Vedas, one needs expert brahmanas known as yajñika-brahmanas. In Kali-yuga, however, there is a scarcity of such brahmanas. Therefore in Kali-yuga the sacrifice recommended in sastra is sankirtana-yajña (yajñaih sankirtana-prayair yajanti hi sumedhasah). Instead of spending money unnecessarily on performing yajñas impossible to perform in this Age of Kali because of the scarcity of yajñika-brahmanas, one who is intelligent performs sankirtana-yajña. Without properly performed yajñas to satisfy the Supreme Personality of Godhead, there will be scarcity of rain (yajñad bhavati parjanyah). Therefore the performance of yajña is essential. Without yajña there will be a scarcity of rain, and because of this scarcity, no food grains will be produced, and there will be famines. It is the duty of the king, therefore, to perform different types of yajñas, such as the asvamedha-yajña, to maintain the production of food grains. Annad bhavanti bhutani. Without food grains, both men and animals will starve. Therefore yajña is necessary for the state to perform because by yajña the people in general will be fed sumptuously. The brahmanas and yajñika priests should be sufficiently paid for their expert service. This payment is called daksina. Ambarisa Maharaja, as the head of the state, performed all these yajñas through great personalities like Vasistha, Gautama and Asita. Personally, however, he was engaged in devotional service, as mentioned before (sa vai manah krsna-padaravindayoh). The king or head of state must see that things go on well under proper guidance, and he must be an ideal devotee, as exemplified by Maharaja Ambarisa. It is the duty of the king to see that food grains are produced even in desert countries, what to speak of elsewhere.