Deceitful - Better, abundant. Very lavish is the enemy of the kisses that cover perfidy, but lavish of them only. His courtesy goes no deeper.
SDA Bible Commentary (limited)
Volume 1-7
6. Faithful.Heb.ne’emanim, from the root ’aman, “to support,” “to be firm,” “to be true and faithful.” The “amen” with which we conclude our prayers comes from this root. The kindly, well-meant rebuke of a friend (v.5) is said to be of this character.