The early afternoon tweet and Instagram post came after Mr. Flynn pleaded guilty on Friday to lying to Mr. Comey’s F.B.I. about conversations he had with the Russian ambassador last December. In doing so, Mr. Flynn brought the special counsel investigation into Russian interference during the election into Mr. Trump’s inner circle.
Mr. Comey’s post reflects a habit on display in recent months in which he has appeared to use a carefully chosen quotation to allude to someone or something in the news. Of course, all subtweets — the term of Twitter art for critical tweets with unnamed targets — have deniability. Mr. Comey could not be immediately reached to deny (or confirm) that he was subtweeting Mr. Flynn. He gave no further clue on Twitter.
On Oct. 30, the day the special counsel filed the first charges in its investigation, Mr. Comey tweeted a quotation about democracy and justice by Reinhold Niebuhr, the American theologian who was the focus of his college thesis. (Mr. Comey had used the theologian’s name as a pseudonym on the Twitter account until recently.)
A few weeks later, on Nov. 19, Mr. Comey tweeted a quotation about leadership just hours after Mr. Trump suggested that he should have left an American college basketball player in Chinese prison, a response to the athlete’s father suggesting that Mr. Trump played little role in freeing his son in the first place.
But Mr. Comey’s tweets are not exclusively quotations. About two hours after he tweeted the Bible verse, he weighed in on a different subject in the news, sharing a “Saturday Night Live” video clip about sexual harassment.
“With four daughters, this skit is funny, painful, and personal for me,” he wrote. “All of us are responsible for the culture of our workplaces, which we protect by insisting on transparency and integrity.”