G4642–σκληρός–sklēros

"He also who had received the one talent came and said, 'Lord, I knew you that you are a hard man, reaping where you did not sow, and gathering where you did not scatter.

σκληρὸς sklēros “hard”

Therefore many of his disciples, when they heard this, said, "This is a hard saying! Who can listen to it?"

σκληρός sklēros “Difficult”

He said, "Who are you, Lord?" The Lord said, "I am Jesus, whom you are persecuting.

σκληρόν sklēron “hard”

When we had all fallen to the earth, I heard a voice saying to me in the Hebrew language, 'Saul, Saul, why are you persecuting me? It is hard for you to kick against the goads.'

σκληρόν sklēron “[It is] hard”

Behold, the ships also, though they are so big and are driven by fierce winds, are yet guided by a very small rudder, wherever the pilot desires.

σκληρῶν sklērōn “strong”

to execute judgment on all, and to convict all the ungodly of all their works of ungodliness which they have done in an ungodly way, and of all the hard things which ungodly sinners have spoken against him."

σκληρῶν sklērōn “harsh [things]”