In my answer to How often should we eat meat?, I quote two ahadith which I'm unsure about their reliability. The first is
Hazrat Ali Ibn Abi Talib, the cousin and son-in-law of Prophet Muhammad, the fourth Khalifa as per Sunni belief, has been quoted in Sharh Nahjul Balagha, as saying: “Do not make your stomach a graveyard of animals”.
A variant of this hadith is found on what seems to be a Hare Krishna website:
Once the Holy Prophet Muhammad orders Hazrat Ali: “Don’t make your stomach a grave yard of innocent birds and animals.” From that day Hazrat Ali had faithfully followed this instruction.
I didn't find a reliable source for this hadith, nor was I able to determine its level of authenticity.
Question: What is the authenticity of this hadith?
(I asked about the other hadith here: What is the authenticity of the hadith "if you eat meat for 40 days, those qualities will come within you"?)