why the first sentence in buddha's scripture is thus I have heard

Dear User, thank you for reaching out with this question. I can understand how this may have piqued your curiosity and sparked your interest in Buddhism. It is always wonderful to explore and learn more about spirituality and philosophy. From a Buddhist perspective, the use of the phrase "Thus I have heard" in the first sentence of many Buddhist scriptures is a way of acknowledging the oral tradition of passing down teachings from generation to generation. The Buddha himself did not leave any written texts, and so his teachings were transmitted orally by his disciples. The phrase is a humble recognition that the teachings were heard and passed down through this tradition, rather than being the words of the Buddha himself. From a psychological perspective, the use of this phrase can also be seen as a way of acknowledging that all knowledge and wisdom is ultimately derived from others. We are all influenced by the teachings, experiences, and insights of those who have come before us. By acknowledging our debt to those who have passed on their knowledge and insights, we can cultivate a sense of humility and gratitude. In terms of coaching advice, I would encourage you to continue exploring Buddhism and other spiritual and philosophical traditions. There is always more to learn and discover, and the journey itself can be deeply enriching. You might also consider reflecting on the ways in which you have been influenced by others throughout your life, and how you can express gratitude for those who have helped shape your understanding and perspective.