Via Daily Dharma / Ask Questions

Then the Blessed One addressed the monks, “If even a single monk has any doubt or indecision concerning the Buddha, Dhamma, or Sangha, the path or the practice, ask. Don’t later regret that ‘The Teacher was face-to-face with us, but we didn’t bring ourselves to cross-question him in his presence.’”

—Thanissaro Bhikkhu, "Skill in Questions"