git show 550a38b52
generate a quite close content while it is not exactly a patch.
You can use this command
git format-patch -1 550a38b52
It will generate a file like
0001-<commit-title>.patch in the current directory.
The common commit id and string can be used such as
For how to apply the patch,
patch -p1 < 0001-commit-title.patch