'Solemn' in the Bible

And he said unto them, This is that which Jehovah hath spoken, Tomorrow is a solemn rest, a holy sabbath unto Jehovah: bake that which ye will bake, and boil that which ye will boil; and all that remaineth over lay up for you to be kept until the morning.

Six days shall work be done, but on the seventh day is a sabbath of solemn rest, holy to Jehovah: whosoever doeth any work on the sabbath day, he shall surely be put to death.

Six days shall work be done; but on the seventh day there shall be to you a holy day, a sabbath of solemn rest to Jehovah: whosoever doeth any work therein shall be put to death.