The Vedas are compared to the desire tree because they contain all things knowable by man. They deal with mundane necessities as well as spiritual realization. The Vedas contain regulated principles of knowledge covering social, political, religious, economic, military, medicinal, chemical, physical and metaphysical subject matter and all that may be necessary to keep the body and soul together. Above and beyond all this are specific directions for spiritual realization.
-Shrimad Bhagavatam Canto 1 Chapter 1 Verse 3, Translation and Purport

मुनय: साधु पृष्टोऽहं भवद्भ‍िर्लोकमङ्गलम् ।
यत्कृत: कृष्णसम्प्रश्नो येनात्मा सुप्रसीदति ॥ ५ ॥
O sages, I have been justly questioned by you. Your questions are worthy because they relate to Lord Kṛṣṇa and so are of relevance to the world’s welfare. Only questions of this sort are capable of completely satisfying the self.
-SB 1.2.5