My meditation teacher used this quote but she didn’t know the source of it. It’s really quite beautiful, but I am pretty suspicious it doesn’t come from the mouth of the Buddha.
“It is in this way that we must train ourselves: By liberation of the self through love, We will develop love, We will practice it, We will make it both a way and a basis, Take a stand upon it, store it up, and thoroughly set it going.” – the Buddha
I was suspicious too, but this is actually a canonical quote, and as you Geoffrey says, it’s rather lovely. It’s from the Samyutta Nikaya, and in Bhikkhu Bodhi’s translation you’ll find it on page 708:
“Therefore, bhikkhus, you should train yourselves thus: ‘We will develop and cultivate the liberation of mind by lovingkindness, make it our vehicle, make it our basis, stabilize it, exercise ourselves in it, and fully perfect it.’ Thus should you train yourselves.”
So this is basically an accurate quote. I don’t know where Geoffrey’s teacher’s version of the quote comes from. The only Samyutta Nikaya I have is Bhikkhu Bodhi’s.
I think what the Buddha was doing here was encouraging the monks to set their intentions. Those intentions outline a progressive sequence leading roughly from bringing lovingkindness into being, making it increasingly a part of our lives, and finally perfecting it so that there are no thoughts, words, or actions that are not imbued with lovingkindness.
The word translated in the two versions as either “love” or “lovingkindness” is metta. These days my own preferred translation of this term is “kindness.” Metta is the desire that beings be happy and free from suffering, not because we necessarily, know them, like them, are related to them, or in any way connected with them, but simply because we know it’s the nature of beings to wish these things.