Question: It is understandable that the Mishnah taught (see above (b)) that one may not water using underground water pits (since it involves a large amount of toil). However, why is it prohibited to water from collected rainwater (that does not involve much toil)?

Answer - R. Yochanan: They decreed against using rainwater, since it is similar to underground pits, lest one use underground pits.

R. Bisna quoting Rebbi: Rainwater and underground pits are only prohibited on Chol Hamoed, but in Sheviis it is permitted to water even from underground pits, since the Mishnah permitted watering irrigated fields.

Question: What is the difference between Sheviis and Chol Hamoed?

Answer: Sheviis - since it is permitted in Melacha, they permitted it both in acts that involve toil and acts that do not.

Chol Hamoed - Since Melacha is prohibited, they only permitted acts that prevent financial loss and they must also not involve toil.

Answer #2: Some differentiate as follows - they permitted Sheviis since it extends for a long period of time.

As for Chol Hamoed, they prohibited it since it lasts for only a short time.

Question: Should we view the last seven days of Sheviis as a short period of time and they should be prohibited, or do we not differentiate? (This question remains unanswered.)

Question (R. Yirmiyah): How do we view rainwater that is still flowing down the mountains? Are they like rainwater or like spring water?

Answer from here: The following are considered 'Mai Tamtzius" - as long as it is raining and the mountains are bubbling over from the rain. If the rain stopped and the mountains are still bubbling, it is Mai Tamtzius. If the mountains stop bubbling, it is called "Mai Gaviim".

Question: How long is it called rainwater rather than spring water?

Answer (Chiya bar Bun quoting R. Yochanan): Until the pits grow in which the water is held.

Answer #2 (R. Elazar bei Yosi quoting R. Tanchum bei R. Chiya): Until they become like duck's feet (become wider and wider).

Question (R. Yirmiyah): During the break when the rain stopped and then restarted (during which time the pit grew), when does it become considered like a spring - retroactively or from then onwards?

Question: If it is anyway prohibited to water from it until after it becomes wider, what is the difference?

Answer: If he immersed into it needles and tubes (to be purified) - if it retroactively becomes a spring, they are pure; if it is only from then onwards, they are still impure.

Question (R. Elazar bei R. Yosi): Is a shallow furrow (an aqueduct) considered to be like an underground pit? If a pit is continuously filling up from a spring, it is certainly permitted to water with it; but here, the spring stopped flowing in - since it is actually spring water, do we refrain from prohibiting it?

Proof: (Our Mishnah taught) But one may not water from collected rainwater or from underground water pits.

What is the case? If the rain is falling, it is considered connected to the Mediterranean sea! Rather, it is when the rain stopped.

If so, it is like a pool that was filling up from a spring and the flow stopped, and you said that one may not water from it!

Question: If a pool was filling up from an underground pit and a spring started to flow into it, may one use it for watering?

Proof: If the spring water from an irrigated field is seeping into a pool in another (lower) irrigated field, one may use it for watering.

R. Yirmiyah: This is true when the water is still seeping.

Is it just the seeping that allows us to water from it? It is because of the pool full of water, and the ruling is that one may water from it. This shows that if a pool was filling up from an underground pit and a spring started to flow into it, one may use it for watering.

Support (Shmuel - Beraisa): If water storage pits were filled before the festival, one may not use them for watering on the festival.

If there is a water channel passing between them (flowing from a spring to the pit), one may water with them and one need not refrain.

The Mishnah had taught: One may not make Ugiyos (water collection gullies) around vines.

The Mishnah is referring to small pits around the stem of a vine. We learn this in a Mishnah - the first four handbreadths of the handle of a Badid (a metal shovel used to dig Ugiyos) are considered to be part of the utensil itself.