法華義疏 9.59

9.59

酒有歡適義，喻聞教歡喜自知作佛；二、酒有昏迷義，喻其因教起迷。今喻大乘，正欲明三根聲聞中途迷教義，故正借酒為喻，是以命初即云醉酒而臥。

First, wine has the sense of joy and pleasure, illustrating that upon hearing the teaching one rejoices and knows oneself to be a Buddha; second, wine has the sense of intoxication and delusion, illustrating that on account of the teaching one generates delusion. Here, illustrating the Mahāyāna is precisely intended to clarify the meaning of the śrāvakas of the three capacities becoming deluded by the teaching along the way; therefore wine is appropriately borrowed as a metaphor, and hence at the very outset it says, "he drank wine, became drunk, and lay down."