From Luke 12 (NIV):

47 “The servant who knows the master’s will and does not get ready or does not do what the master wants will be beaten with many blows. 48 But the one who does not know and does things deserving punishment will be beaten with few blows.

I’m so glad that it explicitly says “servant” there. Because otherwise, you just know that some ungodly scoffer would say that Jesus endorses not just slavery, but the beating of slaves.

But as usual, God’s word (properly translated) is crystal-clear on the subject, and of course Jesus doesn’t condone slavery, and hasn’t done so since 1865.