According to this sentence in the altar sutra, "the lower people have wisdom, but the upper people have no wisdom", it can be concluded that the word "nothing" should be read as "Mo". This means that although he is the most ordinary person, he can also have great wisdom, and even great people may bury it. This explanation is more closely related to the meaning of the upper and lower sentences.
Therefore, the word "nothing" should be pronounced as "Mo" instead of "Mei".