/usr/share/zsh/help/source is in zsh-common 5.3.1-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | source file [ arg ... ]
Same as `.', except that the current directory is always
searched and is always searched first, before directories in
$path.
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