פירוש על שבת 41:12

[If] it becomes extinguished: The Channuakah light.

And it is permissible to use its light: And you may say, "From where did Rava [know] that Rav Huna held that it is permissible to use its light; maybe that which he said, 'We may not light [it] on Shabbat,' is because he held that if it becomes extinguished, he is bound to it, but he may not light it on Shabbat?" But it can be said (answered) that, if so, he would not have needed to say, "both on Shabbat and during the week" - since it is [for] the same reason. Rather, he should have said, "We do not light" - without differentiation. [But] since he said, "both on Shabbat and during the week," we understand from it that there is still another reason for not lighting on Shabbat, besides the reason for the week; and that is lest he tilt it. And if so, he holds that it is permissible to use its light. However Rav, who said, "We may light both on Shabbat and during the week," could not have found to say, "we light," without differentiation. For I would have thought that it was [permissible] specifically during the week, but on Shabbat we may not light [it], lest he tilt [it]. As all things being equal, I would not have said that anyone would be stringent to forbid using its light. And so is the law, that it is forbidden to use the light of the Channukah light, like Rav and Rabbi Yochanan. And Abbaye also accepted this [to be the law]. And it is also implied later that Rav Yosef holds like this. And [if] it becomes extinguished, one is not bound to it - since all of them hold like this; whereas Rav Huna is alone, so the law is not like him.

One is bound to it: To fix it. Hence he needs from the outset to make it proper, lest he be negligent and not fix it [if it goes out].

And it is permissible to use its light: Hence it is forbidden on Shabbat, lest he tilt [it] (to prevent it from feeding fuel to the fire) for the sake of [another] use.