Abu Dawud Book 20, Hadith Number 3689.

Narated By Buraydah ibn al-Hasib : The Prophet (PBUH) said: I forbade you three things, and now I command (permit) you for them. I forbade you to visit graves, now you may visit them, for in visiting them there is admonition. I forbade you drinks except from skin vessels, but now you may drink from any kind of vessels, but do not drink an intoxicant. I forbade you to eat the meat of sacrificial animals after three days, but now you may eat and enjoy it during your journeys.