What are the criticism from white clergymen in Birmingham that dr king is responding to?

In his "Letter from Birmingham Jail," Dr. Martin Luther King Jr. responds to criticisms from white clergymen who labeled his actions as "unwise and untimely." They argued that the struggle for civil rights should be pursued through legal channels and patient negotiation rather than direct action. King counters this by emphasizing the urgency of the situation, highlighting how African Americans have waited long enough for justice and that nonviolent protest is necessary to create a sense of urgency for change. He also critiques their call for patience, arguing that "justice too long delayed is justice denied."