'a mighty hand' is a grammatically correct phrase that is commonly used in written English.
It is generally used to describe someone or something with immense power or control. For example, one might write, "With a mighty hand, the king commanded the troops to march forward."
No one should doubt that Mr. Bloomberg had a mighty hand in formulating this announcement.
From the window of our room we could see the Black Cuillin Mountains, their towering summits silhouetted against the sky as if drawn by a mighty hand.
He did not mention that, as chief justice, he would have a mighty hand in shaping the contours of the strike zone.
As you may have heard, God took the Israelites out of slavery in Egypt with a mighty hand and an outstretched arm.
It is probably fortunate that, despite its mighty hats, fate has not yet dealt the Monster Raving Loony Party a mighty hand.
Speaking to the BBC, he explicitly ruled out a deal with the Tories but added: "Fate seems to have dealt us a mighty hand between ourselves and Plaid Cymru.
While early advocates were instrumental in saving fantastic structures with true historical and aesthetic value, the process is now so intrusive that even a building that merely abuts a historic district falls under the mighty hand of a powerful commission.
It was not my wisdom or knowledge or senses that pulled me out in a fraction of a second it was THE MIGHTY hand of my Heavenly Father who had appointed Archangel Michael for my protection.
Concentration of media ownership is consolidating press power into a few mighty hands.
A newscaster is heard using the phrase "mighty hand of fate," an allusion to the wonderfully portentous voice-over by William Conrad, who each week spoke of fate and flight in a famous introductory sequence.
The first minister said "fate has moved its mighty hand" after a punter in the sparsely attended hall won her game when Salmond called out a number the SNP has put at the core of its campaign: 74.
