I very much love this prayer.
The verse I have been contemplating is this one:
It is not existent ~ even the Victorious Ones do not see it.
It is not nonexistent ~ it is the basis of all samsara and nirvana.
This is not a contradiction, but the middle path of unity.
May the ultimate nature of phenomena, limitless mind beyond extremes, be realised.
From this translation
. And here is a link
to a long commentary by Tai Situpa Rinpoche (in .PDF format).
Learn to do good, refrain from evil, purify the mind ~ this is the teaching of the Buddhas