Bijan Mortazavi: Pray for my wife, she has to undergo brain surgery

It's fine to keep your message short and sweet. If you don't know the person very well, a simple message still shows them that you care. You can use this one before surgery or during recovery. Here are a few more generic phrases you could use for an acquaintance or colleague:

• "We're all sending our best wishes and hopes for a speedy recovery."
• "Thinking of you."
• "Looking forward to having you back in the office when you're ready!"