'Solemn' in the Bible

On the first day [of the feast] you shall have a holy and solemn assembly, and on the seventh day there shall be another holy and solemn assembly; no work of any kind shall be done on those days, except for the preparation of food which every person must eat—only that may be done by you.

He said to them, “This is what the Lord has said: ‘Tomorrow is a solemn rest, a holy Sabbath to the Lord’; bake and boil what you will bake and boil [today], and all that remains left over put aside for yourselves to keep until morning.”