Part 5 - How these are classified as the external secret mantra

As for these great tantras:

These are the outer mantra. We cannot meditate
On yab yum deities, united in sexual union.
There is no usage of the five meats and the five amritas.
They always stay within their rites of purification.

In kriya and upa(ya) tantra there are male and female deity sattvas. These deities of vidya mantra and dharani abide in those tantras in the manner of master and servant and companion respectively. There is no union with them. In yoga tantra the great square arrangement of the mandala is taught as sambhogakaya, but there is no union with it. By meditating successively on upaya and prajña, the developing and completion stages are separate. There is no use of the five meats and five amritas as samaya substances. These are grasped as defiled objects, and therefore one must remain with purifying actions. The Tantra of the Play of the Great Power (dbang chen rol pa’i rgyud) says:

Clouds of enjoyment of upaya and prajña are the principal means of establishing wisdom.
As for the five meats and the five amritas and the highest play of mahasukha
These wonderful ways of being are other than what is to be found here.
Those with the lesser fortune of tormenting rites of purity do not have such things as these.