Insert multiple lines of text before specific line using Bash

Question

I am trying to insert a few lines of text before a specific line, but keep getting sed errors when I try to add a new line character. My command looks like:

Answer 1

To be POSIX compliant and run in OS X, I used the following (single quoted line and empty line are for demonstration purposes):

sed -i "" "/[pattern]/i\\
line 1\\
line 2\\
\'line 3 with single quotes\`
\\
"