In the post, Sanford transitioned from his son's "painful" loss at a football championship game to a lesson he says Trump needs to learn about how there "can be great wisdom in silence."
"One of the things I have slowly learned in hard and painful fashion is that there can be great wisdom in silence," Sanford wrote. "Donald Trump needs to do this now that he is moving from campaign world to governance. Every action does not require an equal and opposite reaction. To continue this is to be nothing more than slave to the next antagonist and their words."
Sanford said that rapid response to small things can be "lethal" in elected office. He also called Trump's tweets demanding an apology from the cast "crazy."
"In campaign world, rapid response is vital. In governance, it can be lethal if it’s in reaction to things small and unimportant," he wrote. "It just strikes me as crazy that the soon-to-be leader of the free world would be waking up each morning this weekend and tweeting comments about what someone said at a play in New York."
The Republican congressman urged Trump to keep the First Amendment in mind and have perspective on what is truly important.
"When someone does exercise their right, demands to recant words are counterproductive," Sanford wrote. "Doing so will only invite more on which to demand apology. Mr. Trump has far more important things on his plate than trying to pry words out of someone exercising the very American right that was created at the time of Hamilton, Jefferson, Washington, and others who believed freedom to say what we liked - and do not like - was part and parcel to liberty."