A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 8 May 2014
So the rules state that:
"Before a player gains Honor from attaching a card to one of his or her dishonorable Personalities, the Personality's re-honoring is substituted for the Honor gain"
However the definition of "from":
"The source is the card that the effect, action or targeting is printed on, or the rulebook if it is printed there"
So normally attaching the card is "from" the rulebook because that is where the action is printed. Some cards gain you honor after attaching them to personalities and since those traits on printed on those cards they come "from" that card. So why is it that the honor gains would re-honor personalities? The honor gain is not "from" the Equip but "from" the attaching card itself.
A player, 8 May 2014
You're reading it too literally, but that phrase is not to be interpreted under the definition of "from" (which applies to cards, mostly, not to procedures) but rather under regular English. When the rule says "from attaching", it doesn't refer exclusively to the attaching effect from the Equipping action but rather to the entire process of attaching, including effects triggered by it. "After you Equip this card, gain X" is an effect derived from Equipping, it's triggered by it. That rulebook paragraph refers to all effects triggered by the card being attached, such as Sparrow Clan Aide's trait, or Blessed Sword's. Those effects come not from the Equipping action itself but are triggered by it, and that's meaning of the phrase you quoted.
PS Certainly the honor gain comes from the card itself, if another effect tries to verify the source of the gain the source is the attachment