The truth behind deception

Jordin noted in the comments on Deception that it is quite possible that Sarai was his half sister and so he was not technically lying when he told Pharoah that. But as he was not really giving Pharoah the whole picture, his sin may not have been technically 'lying' but a sin of omission. And then in Genesis 20, Abram repeats the same scenario, this time replacing Pharoah with Abimelech and God has to let Abimelech know the truth in a dream. As I said to Jordin today "Did he not learn the first time?", to which she said "And how many times do we not learn the first time?". I'd say my fair sister has a point. (to provide full disclosure in keeping with the post: Jordin is not my biological sister, but my sister in Christ:)