'Heavy' in the Bible

And Moses said to Yahweh, "Please, Lord, I [am] not a man of words, {neither recently nor in the past nor since your speaking} to your servant, because I [am] heavy of mouth and of tongue."

But the hands of Moses [were] heavy, and they took a stone and placed it under him, and he sat on it; Aaron and Hur supported his hands, {one on each side}, and his hands [were] steady until {sundown}.

{And} on the third day, when it was morning, there was thunder and lightning, and a heavy cloud over the mountain and a very loud ram's horn sound, and all the people who [were] in the camp trembled.