Matthew 12:38-39 New American Bible (Revised Edition) (NABRE)
38 Then some of the scribes and Pharisees said to him, “Teacher,[a] we wish to see a sign from you.” 39 He said to them in reply, “An evil and unfaithful[b] generation seeks a sign, but no sign will be given it except the sign of Jonah the prophet.
Matthew 16:1-4 New American Bible (Revised Edition) (NABRE)
The Demand for a Sign. 1 [a]The Pharisees and Sadducees came and, to test him, asked him to show them a sign from heaven. 2 [b]He said to them in reply, “[In the evening you say, ‘Tomorrow will be fair, for the sky is red’; 3 and, in the morning, ‘Today will be stormy, for the sky is red and threatening.’ You know how to judge the appearance of the sky, but you cannot judge the signs of the times.] 4 An evil and unfaithful generation seeks a sign, but no sign will be given it except the sign of Jonah.”[c] Then he left them and went away.