R. Yonah: One who goes tale-bearing, do not trust him with your secrets. Since he does not guard his tongue from Rechilus, he will not guard it from revealing your secrets. Here it teaches that one who reveals secrets, do not speak to him about people's guilt or blemishes. Do not say that even though he reveals secrets, for he thinks that there is no damage via revealing them, but he will not go tale-bearing, for the Torah forbade "Lo Selech Rachil b'Amecha" (Vayikra 19:16). This is wrong. Since he does not rule over his Nefesh to avoid revealing secrets, he will not rule over his Nefesh to avoid going tale-bearing.

Rashi: He talks smoothly to entice you.

R. Yonah: He is not precise about his words. He does not think before speaking, to refine and remove the dross from them. Since he sends his tongue [to say] whatever crossed his Ru'ach, he will also reveal secrets and go tale-bearing. Many damage will come from his company.

Malbim: He speaks folly.

R. Yonah: Do not join with him or be involved with him.

Malbim: Since Etzah is primary, and it is ruined via revealing secrets, you must guard greatly from those who normally reveal secrets. There are three such types. (a) One whose nature is to reveal secrets, and his Ru'ach is not trustworthy. (b) One who goes tale-bearing. Also he is wont to reveal secrets via his Rechilus. (c) One who speaks enticement with his lips. Since he normally speaks much, he will not guard secrets from his folly.