It's a nice idea to have a tattoo in memory of your grandfather!
That phrase is part of an old Irish blessing:
"May the road rise to meet you.
May the wind be ever at your back.
May the sun shine warm upon your face,
and the rains fall soft upon your fields.
And until we meet again,
may God hold you in the palm of his hand."
I'm sure there are members of our Community who will help you in translating the phrase above. In the meantime, we have a thread
where you may find helpful information. Once you got it, don't hesitate to upload a photo of your tattoo!
Have a great day.