it. she: referring to the "commandment" or "law" of Proverbs 6:20, which are feminine.
sleepest. liest down.
talk. commune. Three, the number of Divine completeness (App-10). Not four (as some suppose) and one "dropped out"!
Related Commentaries of Proverbs 6:22
Proverbs 6:22
22 When thou goest, it shall lead thee; when thou sleepest, it shall keep thee; and when thou awakest, it shall talk with thee.