give (one) a line
To speak deceptively to one. In this phrase, "line" refers to a prepared response, perhaps one intended to be what the listener wants to hear. Don't give me a line, tell me the truth—what's the real reason you missed my party?
give someone a line
and feed someone a lineto lead someone on; to deceive someone with false talk. Don't pay any attention to John. He gives everybody a line. He's always feeding us a line.