SYNTAX:
slip <object> <into> <container>
slip <object> <into> <person's container>
slip <object> <to> <person>
slip <object> to here
The slip verb is used to surreptitiously pass something to someone, or to covertly place something in a container (not necessarily your own).
Examples:
slip coins to man
slip bloody dagger into braman's satchel
slip dart into moneybag