Finger of God is mention at least twice in Scriptures
Luke 11:20, in which Jesus referred to the power by which He casted out demons. Hence we see God's Grace and the human race deliverance from the bondage of sin thru Jesus Christ.
The magicians speak of it, when noting to Pharaoh that it was God power that Moses was operating in, Exodus 8:19; see also Psalms 8:3. Hence we see God's Grace in delivering the children of Israel out of Egypt.
IMO, this is why Noah is the first one mention to find grace. Just as Moses preached to the Jews their deliverance from bondage in Egypt, so we as Christians have deliverance from sin's bondage by Christ Jesus. We also see that Noah made an attempt to preach unto the ungodly they just would not listen, II Peter 2:5. God was willing to grant grace unto many but just 8 souls heeded the message, But God is so powerful yet so meek that He will supply our need thru His Son Jesus Christ but will give us free choice of rather we want/need it or not.