How to grep (search) committed code in the Git history

Question

I have deleted a file or some code in a file sometime in the past. Can I grep in the content (not in the commit messages)?

A very poor solution is to grep the log:

Answer 1

Jeet's answer works in PowerShell.

git grep -n  $(git rev-list --all)

The following displays all files, in any commit, that contain a password.

# Store intermediate result
$result = git grep -n "password" $(git rev-list --all)

# Display unique file names
$result | select -unique { $_ -replace "(^.*?:)|(:.*)", "" }