'Solemn' in the Bible

The cook picked up the thigh and what was attached to it and set it before Saul. Then Samuel said, “Notice that the reserved piece is set before you. Eat it because it was saved for you for this solemn event at the time I said, ‘I’ve invited the people.’” So Saul ate with Samuel that day.

When the army came to the forest, look! [There was] honey flowing, but no one put his hand to his mouth, for the army was afraid of the solemn oath.

Then a man from the army informed [him] and said, "Your father made the army swear a solemn [oath], saying, 'Cursed be the man who eats food today,'" so the army [is] exhausted.