git config core.sshCommand "ssh -i ~/.ssh/id_rsa_example -F /dev/null"
git pull
git push
# Other way
edit .git/config file like:
[core]
sshCommand = ssh -i ~/.ssh/id_rsa_example -F /dev/null
git config --local core.sshCommand "ssh -i ~/.ssh/id_rsa_example -F /dev/null"