[487.] Best draw: we had best draw our swords.
[489.] Defence is a good cause, etc., i.e. ‘in defending ourselves we are engaged in a good cause, and may Heaven be on our side.’
[490.] That hallo. We are to understand that the Attendant Spirit has halloed just before entering; this is shown by the stage-direction given in the edition of Comus printed by Lawes in 1637: He hallos; the Guardian Dæmon hallos again, and enters in the habit of a shepherd.
[491.] you fall, etc., i.e. otherwise you will fall on our swords.
[493.] sure: see [note], l. 246.
[494.] Thyrsis, Like Lycidas, this name is common in pastoral poetry. In Milton’s Epitaphium Damonis it stands for Milton himself; in Comus it belongs to Lawes, who now receives additional praise for his musical genius. In lines [86-88] the compliment is enforced by alliterative verses, and here by the aid of rhyme ([495-512]). Masson thinks that the poet, having spoken of the madrigals of Thyrsis, may have introduced this rhymed passage in order to prolong the feeling of Pastoralism by calling up the cadence of known English pastoral poems.
[495.] sweetened ... dale; poetical exaggeration or hyperbole, implying that fragrant flowers became even more fragrant from Thyrsis’ music.
[496.] huddling. This conveys the two ideas of hastening and crowding: comp. Horace, Ars Poetica, 19, “Et properantis aquae per amoenos ambitus agros.” madrigal: a pastoral or shepherd’s song (Ital. mandra, a flock): such compositions, then in favour, had been made by Lawes and by Milton’s father.
[497.] swain: a word of common use in pastoral poetry. It denotes strictly a peasant or, more correctly, a young man: comp. the compounds boat-swain, cox-swain. See Arc. 26, “Stay, gentle swains,” etc.
[499.] pent, penned, participle of pen, to shut up (A.S. pennan, which is connected with pin, seen in pin-fold, l. [7]). forsook: a form of the past tense used for the participle.