Does a Moon Sickle's bonus healing apply to each roll of Healing Spirit?

Question

I was going through the description for Moon Sickle from Tasha's Cauldron of Everything, and it states in the second paragraph (emphasis mine):

When you cast a spell that restores hit points, you can roll a d4 and add the number rolled to the amount of hit points restored, provided you are holding the sickle.

The text for Healing Spirit states:

Until the spell ends, whenever you or a creature you can see moves into the spirit's space for the first time on a turn or starts its turn there, you can cause the spirit to restore 1d6 hit points to that creature (no action required).

Seeing as the bonus healing from the Moon Sickle is triggered when a spell is cast, and not when healing amount is rolled, would Healing Spirit benefit from the bonus?

Personally, I feel like it wouldn't RAW, but it feels like an oversight, so maybe it would RAI?

Answer 1

At most, it would apply to only one roll of Healing Spirit and only if the DM allows it

Rule wording is ambiguous

The ambiguity here results from the unwritten assumption in the Moon Sickle's description that healing spells generally heal immediately when they are cast. And if all healing spells did that, there would be no issue.

However, Healing Spirit does not heal immediately upon being cast (and, in fact, may not ever heal at all) which then causes a potential split in how you read the following phrase:

When you cast a spell that restores hit points ...

You can read that either as:

1. When you cast a spell that restores hit points [immediately as part of its casting] ...
2. When you cast a spell that restores hit points [at any point the spell is active] ...

Neither one is strictly backed up or negated by rules text that I can find, so that leaves it up to the DM at your table to decide.

Neither interpretation gives a bonus on every roll of Healing Spirit

Interestingly, regardless of which interpretation your DM goes with, the bonus healing would not apply to each roll of Healing Spirit.

In interpretation 1, the bonus would not apply at all since Healing Spirit does not heal immediately upon casting.

In interpretation 2, the bonus would apply once since it says

When you cast a spell that restores hit points, you can roll a d4 and add the number rolled to the amount of hit points restored

In other words, you cast a healing spell and it increases the total number of hit points restored per casting by 1d4. Thus Healing Spirit would only get 1 additional 1d4 of healing over the entire course of the spell.

My ruling

My personal thought and ruling at my table would likely be to keep things simple and interpret it as healing spells that heal immediately upon casting (interpretation 1). This has the dual benefit of being simple and of not increasing the power of an already powerful (some may even argue over-powered) Healing Spirit.

But even if your DM decides to read it as interpretation 2, it would only apply to one roll of Healing Spirit.

Answer 2

Yes, but you only roll the d4 once.

Since the effect of the Moon Sickle does not specify anything about when the spell restores hit points, healing spirit qualifies by virtue of it restoring hit points as part of its effect. Therefore, you can roll a d4; then, you add the number rolled to the amount which healing spirit restores: if you roll a 3, then that casting of healing spirit now restores 1d6+3 hit points.

Note that although you're triggering the effect of the Moon Sickle when you cast the spell, the effect is (optionally) rolling the d4: the hit points need not be restored when you cast the spell.