SB 11.4.22
bhumer bharavataranaya yadusv ajanma
jatah karisyati surair api duskarani
vadair vimohayati yajña-krto ’tad-arhan
sudran kalau ksiti-bhujo nyahanisyad ante
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
To diminish the burden of the earth, the unborn Lord will take birth in the Yadu dynasty and perform feats impossible even for the demigods. Propounding speculative philosophy, the Lord, as Buddha, will bewilder the unworthy performers of Vedic sacrifices. And as Kalki the Lord will kill all the low-class men posing as rulers at the end of the Age of Kali.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
It is understood that in this verse the description of the Lord’s appearance in the Yadu dynasty refers to the appearance of both Krsna and Balarama, who together removed the demoniac rulers who were burdening the earth. Srila Jiva Gosvami has pointed out that the description of the incarnations to deal with sudran, or low-class men, refers to both Buddha and Kalki. Those who misuse Vedic sacrifice to engage in gross sense gratification, such as the sinful killing of animals, are certainly in the category of sudra, as are the so-called political leaders of Kali-yuga who perform many atrocities in the name of state management.