The “tangle” (jaṭā) is the tangled hair or dreadlocks of the Brahmanical jaṭila ascetics, as is made clear in SN 7.6 where a dreadlocked brahmin opens with the same verse. The claim is that jaṭila ascetics are as tangled in their minds by craving as they are in their hair.

In a bold literary conceit, the vast compendium of the Visuddhimagga positions itself as an explanation of this single verse.

Here citta (“mind”) stands for samādhi or jhāna, which is normally the case in the Suttas on the path (eg. cittasampadā = samādhisampadā, cittabhāvanā = samādhibhāvanā, adhicitta = samādhi, etc.)

The previous verse dealt with the one who is practicing; this verse with the perfected one; and the final verse with final extinguishment.