Mettā VS Mettā Jhāna VS Mettā Meditation VS Karuṇā VS Viewing "women" as "mothers"

Viewing "women" as "mothers"

Viewing "women" as "mothers" appeared in Bhāradvājasutta which is not taught about metta, but that sutta was teaching about ordained life keeping (5 saṃvaya):

4. “Great King, the Blessed One who knows and sees is worthy and rightfully enlightened has said: ‘Monks, think of them who are like your mothers as your mother, of them who are like your sisters as your sister, of them who are like your daughters as your daughter. This is the reason for the young monks with black hair, in the prime of youth, not to enjoy sensual pleasures, to devote their life to lead a complete and pure holy life until the end of their lives.”

Mettā VS Mettā Jhāna VS Mettā Meditation & Karuṇā

Metta is wishing to give happiness to the other living life(s).

Mettā jhāna is perfect and successful concentration that focusing in a living life by that wishing-to-give-happiness-method.

Mettā Meditation is that mettā jhāna in advance. The mettā practitioner who attained mettā jhāna in a person, will meditate in the other persons more to attain mettā jhāna in each person, or groups. They will meditate like that until they can attain mettā jhāna in every people as the same quality/volume/feeling/etc. This is called sīmasambheda (mettā limitation cessation).

Karuṅā is wishing to help one cease from suffering, pain, hurt, etc.

So, in venāgasutta:

Here, brahmin, in the morning I put on robes and taking bowl and robes go for alms to the village or hamlet relying on which I abide. After the meal is over and returning from the alms round, I roam in that forest stretch. Finding a heap of grass or leaves, I collect them and sit on them making a cross legged position, keeping the body straight and establishing mindfulness in front. Then I abide pervading one direction with loving kindness, so to the second, the third, the fourth, above, below and across, in every respect, on the whole, entirely grown great, immeasurable and without anger [=sīmasambheda].

The part of purification, CHAPTER IX, THE DIVINE ABIDINGS (Brahmavihára-niddesa) page 291 already explained very well. But I recommend pāli version, because it is easier to understand the relativity of pāli words.

Mettakathā in K.N. Paṭisambhidāmagga is very well one.