I don’t know where “True love is born from understanding” is from, but it’s not from the Buddha, despite many attributions that say it is.
It sounds very like Thich Nhat Hanh, but so far I haven’t found this exact saying in any of his books. There is something similar in one of his books, “Reconciliation: Healing the Inner Child,” with reference to the emotional release of crying:
With the energy discharged, we will be able to look deeply AND TO UNDERSTAND, AND THAT IS WHERE TRUE LOVE IS BORN.
These aren’t the words of Thich Nhat Hanh, however, but of a disciple, Thay Phap An.
In the book, “True Love,” Thich Nhat Hanh writes “Understanding is the essence of love. If you cannot understand, you cannot love.” He also writes, “Without understanding, love is an impossible thing,” and “Love is a true thing if it is made up of a substance called understanding.”
All these quotes are in the ball park, but none is a palpable hit.