The 151st prohibition is that we are forbidden from eating ma'aser sheni when in a state of aninus [mourning].1
The source of this prohibition is G‑d's statement,2 "I have not consumed it while I was in aninus."
In the words of the Mishneh,3 "Ma'aser and bikurim must be brought to Jerusalem; require a verbal declaration;4 and are forbidden to an onein."
This verse also prohibits an onein from consuming sacrificial offerings, as written in the Torah,5 "After such a thing happened to me; if I had eaten the sin offering today, would it have been right in G‑d's eyes?"
The details of this mitzvah are explained in the 8th chapter of Pesachim and the 2nd chapter of Zevachim.
An onein who eats sacrificial offerings or ma'aser sheni is punished by lashes.
