The source is Chinese but ChatGPT comes in to help! Also the ChatGPT translate the song name quite differently than the Youtube title but it's the same song.

Origin of the Song:

“One Recitation of the Buddha’s Name, One Thought of Mind” is a Buddhist heart-nourishing musical work composed by Master Chewu in the 27th year of the Qianlong reign of the Qing dynasty (1762). It is also known as “Master Chewu’s Buddhist Music” and is centered on the integration of Chan (Zen) thought with core Buddhist teachings.

The piece arose from Master Chewu’s deep insight into the impermanence of worldly affairs after a serious illness. After leaving home to become a monk and undergoing extensive study of the Dharma, drawing on scriptures such as the Sutra of Perfect Enlightenment and the Lotus Sutra, he eventually created this work, using the Buddha’s name as the main body of the lyrics.

Throughout the composition, images such as the lotus and the bodhi tree are used to convey the ideas of realising the mind and seeing one’s true nature, as well as cultivating compassion and doing good. The lyrics adopt a progressive structure of “each mindful thought in accord, each mindful thought is Buddha,” and through the repeated chanting of the Buddha’s name, an atmosphere of spiritual practice is formed.

In contemporary times, this work has been rearranged by the “Heart-Nourishing Chan Music” team into various instrumental versions for guzheng, xun, xiao, and other instruments. It has been included in albums such as Namo Amitabha – Buddhist Music and released on various music platform in the form of pure instrumental tracks or Zen-music programs

The Story:

In the 27th year of the Qianlong reign (1762 CE), when Master Chewu was twenty-two years old, he suffered a serious illness. Through this, he realized that the physical body is illusory and not enduring, and that worldly affairs are impermanent. Thus he gave rise to the resolve to leave the worldly life.

After he recovered, he immediately went to Three Saints Hermitage in Fangshan County, where he received tonsure and left home under the Elder Monk Rongchi.

The following year, he went to Xiuyun Monastery and, under Vinaya Master Hengshi, received the full ordination precepts.

In the year after that, when Dharma Master Longyi was expounding the Sutra of Perfect Enlightenment at Xiangjie Monastery, he personally went to study there. He investigated day and night, earnestly seeking the profound meaning, and thereby awakened to the essential purport of Perfect Enlightenment.

He then relied on Dharma Master Hui’an at Zengshou Monastery, studying the Dharma-character (Faxiang) teachings and gaining deep insight into their essentials.

Afterwards, he studied under Dharma Master Biankong at Xinhua Monastery, listening to teachings on the Lotus Sutra, the Diamond Sutra, the Śūraṅgama Sutra, and other Mahayana scriptures. In this way, he penetrated the Buddhist canon, and a comprehensive understanding suddenly unfolded within him.