In 'from' in the verse indicates totality. And in 'from the signs of their Lord' indicates partiality. It means: whenever a proof appears to them from the proofs that require reflection, reasoning, and consideration, they turn away from it: leaving the reflection and not paying attention to it or raising their heads to it, due to their lack of fear and contemplation of the consequences. They have certainly denied, which is a response to an omitted statement, as if it were said: if they are turning away from the signs, then they have denied what is the greatest sign and the largest of it, which is the truth when it came to them, meaning the Qur'an, with which they challenged their eloquence and were unable to match it. Soon they will receive news of that which they used to mock, which is the Qur'an, meaning its news and states, in the sense: they will know by what they mocked. And it will become clear to them that it was not a matter of mockery, and that will be at the time of sending down punishment upon them in this world or on the Day of Resurrection, or at the time of the appearance of Islam and the elevation of its word.