Nothing, not anything explicit anyhow.
We do read of King Josiah fulfilling an old prophecy by burning human bones on the altar at Bethel (2Ki 23:20; 19). While the act did defile the altar, Josiah was in the process of making godly reforms which included putting idolatrous priests to death and setting fire to their bones (2Ki 23:16). The story, however, hardly makes a case for or against cremation.
Most Christians who oppose the practice cite the obvious pattern throughout Scripture. God’s people including Christ himself were buried, not cremated. They note that burial better symbolizes our hope to one day be resurrected, and I don’t think they’re wrong about that. Even so, I won’t call cremation a sin because the Bible doesn’t.
Whether our body is buried or cremated, the end result is the same. All go to one place. All are from the dust, and to dust all return (Ecc 3:20). Cremation just happens to get us there considerably faster than burial.
If you’re asking for my personal preference, I’m not sure I have one. I’ve told my wife to do what she wants with me when I’m gone. And if she opts for the less expensive option of cremation, I trust no one will attempt to make her feel guilty about it. Wounding someone’s conscience when it is weak, assuming the decision to cremate actually represents a weak conscience, is a sin against Christ himself (1Co 8:12). Scripture doesn’t give us the authority to say the same for cremation. In other words, we don’t have the right to make anyone feel guilty about choosing cremation over burial.
The better question is, what does your conscience say about it?