John Gill Commentary Numbers 29:7

"And on the tenth day of this seventh month ye shall have a holy convocation; and ye shall afflict your souls: ye shall do no manner of work;" — Numbers 29:7 (ASV)

And you shall have on the tenth day of the seventh month an holy convocation The month Tisri, as before; so the Targum of Jonathan:

and you shall afflict your souls ; or persons; their bodies by fasting, and their souls by repentance and humiliation; for this was a grand fast, as it is called (Acts 27:9) ,

you shall not do any work [therein] ; see (Leviticus 23:28) .