tad drstva mithunam jatam
tat-that; drstva-seeing; mithunam-couple; jatam-born; rsayah-the great sages; brahma-vadinah-very learned in Vedic knowledge; ucuh-said; parama-very much; santustah-being pleased; viditva-knowing; bhagavat-of the Supreme Personality of Godhead; kalam-expansion.