The quote is from the Clean Coder book:
"Teams are harder to build than projects. Therefore, it is better to form persistent teams that move together from one project to the next and can take on more than one project at a time. The goal in forming a team is to give that team enough time to gel, and then keep it together as an engine for getting many projects done."
This is a really truth. Nothing more good couldn’t happen for developers than working with a great team.