'Sluggish' in the Bible

Speak and say, ‘Thus says the Lord God,“Behold, I am against you, Pharaoh king of Egypt,The great monster that lies in the midst of his rivers,[Boastfully] declaring, ‘My Nile is my own, and I have made it for myself.’

Then Jesus said to them, “O foolish men, and slow of heart to trust and believe in everything that the prophets have spoken!

On this topic we have much to say and it is difficult to explain, since you have become sluggish in hearing.

that ye be not sluggish, but imitators of those who through faith and patience have been inheritors of the promises.