To access files from another branch or past commit without doing a complete checkout, you can either use

git show branch:file
git show commit:file

Rails Long Term Support

Rails LTS provides security patches for old versions of Ruby on Rails (2.3, 3.2, 4.2 and 5.2)

• Prevents you from data breaches and liability risks
• Upgrade at your own pace
• Works with modern Rubies

Read more Show archive.org snapshot

to display, or check out the file into your working directory with

git checkout branch -- file
git checkout commit -- file